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Marta Jordan, 11-10-2018 16:36

 
type: Article
aigaionid: 4703
bibtexid: LliYu2018
title: Global phase portraits for quadratic systems with a hyperbola and a straight line as invariant algebraic curves
author: Llibre, Jaume
author: Yu, Jiang
journal: Electronic Journal of Differential Equations
issn: 1072-6691
year: 2018
number: 141
startpage: 1
endpage: 19
abstract: In this article we consider a class of quadratic polynomial differential systems in the plane having a hyperbola and a straight line as invariant algebraic curves, and we classify all its phase portraits. Moreover these systems are integrable and we provide their first integrals.
file: LliYu2018.Preprint.pdf-27eb2e4766a4413565302d0b6a2a7faf.pdf

type: Article
aigaionid: 4704
bibtexid: LliZha2018c
title: Limit cycles for discontinuous planar piecewise linear differential systems separated by one straight line and having a center
author: Llibre, Jaume
author: Zhang, Xiang
journal: Journal of Mathematical Analysis and Applications
issn: 0022-247X
year: 2018
volume: 467
startpage: 537
endpage: 549
doi: 10.1016/j.jmaa.2018.07.024
keywords: discontinuous piecewise linear differential system
keywords: limit cycle
keywords: non-smooth differential system
abstract: From the beginning of this century more than thirty papers have been published studying the limit cycles of the discontinuous piecewise linear differential systems with two pieces separated by a straight line, but it remains open the following question: what is the maximum number of limit cycles that this class of differential systems can have? Here we prove that when one of the linear differential systems has a center, real or virtual, then the discontinuous piecewise linear differential system has at most two limit cycles.
file: LliZha2018.Preprint.pdf-b8f4184f43fc12ab2221b5e2dcc3d73f.pdf


type: Article
aigaionid: 4520
bibtexid: MarVil2018
title: On the {C}hebyshev property of certain {A}belian integrals near a polycycle
author: Marín, David
author: Villadelprat, Jordi
journal: Qualitative Theory of Dynamical Systems
issn: 1575-5460
year: 2018
volume: 17
number: 1
startpage: 261
endpage: 270
doi: 10.1007/s12346-017-0226-3
keywords: Abelian integrals
keywords: Chebyshev system
keywords: Wronskian
abstract: F. Dumortier and R. Roussarie formulated in [Birth of canard cycles, Discrete Contin. Dyn. Syst. 2 (2009) 723–781] a conjecture concerning the Chebyshev property of a collection $I_0,I_1,...,I_n$ of Abelian integrals arising from singular perturbation problems occurring in planar slow-fast systems. The aim of this note is to show the validity of this conjecture near the polycycle at the boundary of the family of ovals defining the Abelian integrals. As a corollary of this local result we get that the linear span $⟨I_0, I_1, . . . , I_n⟩$ is Chebyshev with accuracy $k = k(n)$.
file: MarVil2017.preprint.pdf-0d9b2631a2252483079c9feffe4638be.pdf


type: Article
aigaionid: 3630
bibtexid: BenFag2018a
title: Singular values and bounded {S}iegel disks
author: Benini, Anna Miriam
author: Fagella, Nuria
journal: Mathematical Proceedings of the Cambridge Philosophical Society
issn: 0305-0041
year: 2018
volume: 165
number: 2
startpage: 249
endpage: 265
doi: 10.1017/S0305004117000469
abstract: Let f be an entire transcendental function of finite order and ? be a forward invariant bounded Siegel disk for f with rotation number in Herman's class H. We show that if f has two singular values with bounded orbit, then the boundary of ? contains a critical point. We also give a criterion under which the critical point in question is recurrent. We actually prove a more general theorem with less restrictive hypotheses, from which these results follow.
file: BenFag2013.pdf-53eb443c4360b511911033ee50890390.pdf


type: Article
aigaionid: 3664
bibtexid: LliVal2018i
title: On the {D}arboux integrability of the {H}indmarsh-{R}ose burster
author: Llibre, Jaume
author: Valls, Clàudia
journal: Acta Mathematica Sinica. English Series
issn: 1439-7617
year: 2018
volume: 34
number: 6
startpage: 947
endpage: 958
doi: 10.1007/s10114-017-5661-1
abstract: We study the Hindmarsh?Rose burster which can be described by the differential system
x?=y?x3+bx2+I?z,y?=1?5x2?y,z?=?(s(x?x0)?z),
where b, I, ?, s, x0 are parameters. We characterize all its invariant algebraic surfaces and all its exponential factors for all values of the parameters. We also characterize its Darboux integrability in function of the parameters. These characterizations allow to study the global dynamics of the system when such invariant algebraic surfaces exist.
file: LliVal2013t.pdf-9d0403a2d819ba9fb8ff964e4ba65d74.pdf


type: Article
aigaionid: 4101
bibtexid: LliOliRod2018
title: On the periodic solutions of the {M}ilchelson continuous and discontinuous piecewise linear differential system
author: Llibre, Jaume
author: Oliveira, Regilene D. S.
author: Rodrigues, Camila A. B.
journal: Computational & Applied Mathematics
issn: 0101-8205
year: 2018
volume: 37
number: 2
startpage: 1550
endpage: 1561
doi: 10.1007/s40314-016-0413-x
keywords: Averaging theory
keywords: continuous piecewise linear differential system
keywords: discontinuous piecewise linear differential system
keywords: Hopf bifurcation
keywords: limit cycles
keywords: Michelson system
abstract: Applying new results from the averaging theory for continuous and discontinuous differential systems, we study the periodic solutions of two distinct versions of the Michel- son differential system: a Michelson continuous piecewise linear differential system and a Michelson discontinuous piecewise linear differential system. The tools here used can be applied to general nonsmooth differential systems.
file: LliOliRod2014.preprint.pdf-7d77334f00d23573fe9b84031d2930e6.pdf


type: Article
aigaionid: 4138
bibtexid: CanLli2018c
title: Zero-{H}opf bifurcations in a hyperchaotic {L}orenz system {I}{I}
author: Cândido, Murilo R.
author: Llibre, Jaume
journal: International Journal of Nonlinear Science
issn: 1749-3889
year: 2018
volume: 25
number: 1
startpage: 3
endpage: 26
keywords: Averaging theory
keywords: hyperchaotic Lorenz system
keywords: periodic orbit
keywords: zero-Hopf bifurcation
abstract: Recently sixteen 3-dimensional differential systems exhibiting chaotic motion and having no equilibria have been studied, and it has been graphically observed that these systems have a period-doubling cascade of periodic orbits providing the route to their chaotic motions. Here using new results on the averaging theory we prove that these systems exhibit, for some values of their parameters different to the ones having chaotic motion, either a zero?Hopf or a Hopf bifurcation, and graphically we observed that the periodic orbit starting in those bifurcations is at the beginning of the mentioned period?doubling cascade.
file: CanLli2017.preprint.pdf-6432eb4fe40b5eb9240064a302860be4.pdf


type: Article
aigaionid: 4141
bibtexid: BarFagJarKar2018
title: Connectivity of {J}ulia sets of {N}ewton maps: A unified approach
author: Baranski, Krzysztof
author: Fagella, Nuria
author: Jarque, Xavier
author: Karpinska, Boguslawa
journal: Revista Mathemática Iberoamericana
issn: 0213-2230
year: 2018
volume: 34
number: 3
startpage: 1211
endpage: 1228
doi: 10.4171/RMI/1022
keywords: connectivity
keywords: Fatou set
keywords: Holomorphic dynamics
keywords: Julia set
keywords: Newton's map
keywords: repelling fixed point
keywords: simple connectivity
abstract: In this paper we give a unified proof of the fact that the Julia set of Newton's method applied to a holomorphic function of the complex plane (a polynomial of degree large than 1 or an entire transcendental function) is connected. The result was recently completed by the authors' previous work, as a consequence of a more general theorem whose proof spreads among many papers, which consider separately a number of particular cases for rational and transcendental maps, and use a variety of techniques. In this note we present a unified, direct and reasonably self-contained proof which works for all situations alike.
file: BarFagJarKar2015.pdf-df1653ccdbd345da4ebb0e33fee66bf8.pdf


type: Article
aigaionid: 4321
bibtexid: LliVal2018b
title: Normal forms and hyperbolic algebraic limit cycles for a class of polynomial differential systems
author: Llibre, Jaume
author: Valls, Clàudia
journal: Electronic Journal of Differential Equations
issn: 1072-6691
year: 2018
number: 83
startpage: 1
endpage: 7
keywords: Algebraic limit cycles
keywords: limit cycles
keywords: Polynomial vector fields
abstract: We study the normal forms of polynomial systems having a set of invariant algebraic curves with singular points. We provide sufficient conditions for the existence of hyperbolic algebraic limit cycles.
file: LliVal2015o.Preprint.pdf-94dbd08cbff2fe8dc0e02dd7e6f84290.pdf


type: Article
aigaionid: 4230
bibtexid: LliRamRamSad2018
title: Centers and uniform isochronous centers of planar polynomial differential systems
author: Llibre, Jaume
author: Ramírez, Rafael Orlando
author: Ramírez, Valentín
author: Sadovskaia, Natalia
journal: Journal of Dynamics and Differential Equations
issn: 1572-9222
year: 2018
volume: 30
number: 3
startpage: 1295
endpage: 1310
doi: 10.1007/s10884-018-9672-0
keywords: Center-focus problem
keywords: polynomial planar differential system
keywords: uniform isochronous centers
abstract: For planar polynomial vector fields of the form \[ (-y X(x,y))\dfrac{\partial }{\partial x} (x Y(x,y))\dfrac{\partial }{\partial y}, \] where $X$ and $Y$ start at least with terms of second order in the variables $x$ and $y$, we determine necessary and sufficient conditions under which the origin is a center or a uniform isochronous centers.
file: LliRamSad2015.Preprint.pdf-3f6d27d52c84c714fb54833395b48cad.pdf


type: Article
aigaionid: 4235
bibtexid: LliVal2018h
title: Global phase portraits of quadratic systems with a complex ellipse as invariant algebraic curve
author: Llibre, Jaume
author: Valls, Clàudia
journal: Acta Mathematica Sinica. English Series
issn: 1439-7617
year: 2018
volume: 34
number: 5
startpage: 801
endpage: 811
doi: 10.1007/s10114-017-5478-y
keywords: complex ellipse
keywords: Invariant algebraic curves
keywords: Phase portrait
keywords: quadratic system
abstract: In this paper we study a new class of quadratic systems and classify all its phase portraits. More precisely, we characterize the class of all quadratic polynomial differential systems in the plane having a complex ellipse $x^2 y^2 1=0$ as invariant algebraic curve. We provide all the different topological phase portraits that this class exhibits in the Poincaré disc.
file: LliVal2015k.Preprint.pdf-67b5ee36f4f3b4c291afbb0eb2eaab1e.pdf


type: Article
aigaionid: 4313
bibtexid: GinLliVal2018b
title: The cubic polynomial differential systems with two circles as algebraic limit cycles
author: Giné, Jaume
author: Llibre, Jaume
author: Valls, Clàudia
journal: Advanced Nonlinear Studies
issn: 2169-0375
year: 2018
volume: 18
number: 1
startpage: 183
endpage: 193
doi: 10.1515/ans-2017-6033
keywords: Cubic systems
keywords: global phase portraits
keywords: Invariant algebraic curves
keywords: invariant ellipse
keywords: limit cycles
abstract: In this paper we characterize all cubic polynomial differential systems in the plane having two circles as invariant algebraic limit cycles.
file: GinLliVal2015b.Preprint.pdf-af649c11633242c2796a7a5ab39fac84.pdf


type: Article
aigaionid: 4180
bibtexid: FreLliMed2018
title: Limit cycles of continuous and discontinuous piecewise-linear differential systems in $\mathbb {R}^3$
author: de Freitas, Bruno R.
author: Llibre, Jaume
author: Medrado, Joao Carlos
journal: Journal of Computational and Applied Mathematics
issn: 0377-0427
year: 2018
volume: 338
startpage: 311
endpage: 323
doi: 10.1016/j.cam.2018.01.028
keywords: limit cycles
keywords: Non-smooth differential systems
keywords: piecewise linear differential systems
abstract: We study the limit cycles of two families of piecewise-linear differential systems in $\R^3$ with two pieces separated by a plane $\Sigma$. In one family the differential systems are only continuous on the plane $\Sigma$, and in the other family they are only discontinuous on the plane $\Sigma$. The usual tool for studying these limit cycles is the Poincar\'{e} map, but here we shall use recent results which extend the averaging theory to continuous and discontinuous differential systems. All the computations have been checked with the algebraic manipulator mathematica.
file: FreLliMed2015.preprint.pdf-b48dac115eddece803d527d94c0b083c.pdf


type: Article
aigaionid: 4209
bibtexid: LliOli2018
title: Quadratic systems with an invariant conic having Darboux invariants
author: Llibre, Jaume
author: Oliveira, Regilene D. S.
journal: Communications in Contemporaray Mathematics
issn: 1793-6683
year: 2018
volume: 20
number: 4
startpage: 1750033
doi: 10.1142/S021919971750033X
keywords: Darboux invariant
keywords: phase portraits
keywords: Quadratic vector fields
abstract: The complete characterization of the phase portraits of real planar quadratic vector fields is very far to be completed. As this attempt is not possible in the whole class due to the large number of parameters (twelve, but, after affine transformations and time rescaling, we arrive at families with five parameters, which is still a big number of parameters), many subclasses have been considered and studied. In this paper we complete the characterization of the global phase portraits in the Poincaré disc of all planar quadratic polynomial differential systems having an invariant conic and a Darboux invariant, constructed using only the invariant conic.
file: LliReg2015.Preprint.pdf-2b64416dc03080412eddd07cd3dea765.pdf


type: Article
aigaionid: 4582
bibtexid: HuaLiaLli2018
title: Non-existence and uniqueness of limit cycles for planar polynomial differential systems with homogeneous nonlinearities
author: Huang, Jianfeng
author: Liang, Haihua
author: Llibre, Jaume
journal: Journal of Differential Equations
issn: 0022-0396
year: 2018
volume: 265
number: 9
startpage: 3888
endpage: 3913
doi: 10.1016/j.jde.2018.05.019
keywords: homogeneous nonlinearities
keywords: limit cycles
keywords: non-existence and uniqueness
keywords: Polynomial differential systems
abstract: In this paper we study the limit cycles of the planar polynomial differential systems \begin{align*}\dot x=ax-y P_n(x,y),\\ \dot y=x ay Q_n(x,y), \end{align*} where $P_n$ and $Q_n$ are homogeneous polynomials of degree $n\geq2$, and $a\in\mathbb R$. Consider the functions \begin{align*} &\varphi(\theta)=P_n(\cos\theta,\sin\theta)\cos\theta Q_n(\cos\theta,\sin\theta)\sin\theta,\\ &\psi(\theta)=Q_n(\cos\theta,\sin\theta)\cos\theta-P_n(\cos\theta,\sin\theta)\sin\theta,\\ &\omega_1(\theta)=a\psi(\theta)-\varphi(\theta),\\ &\omega_2(\theta)=(n-1)\big(2a\psi(\theta)-\varphi(\theta)\big) \psi'(\theta). \end{align*}First we prove that these differential systems have at most $1$ limit cycle if there exists a linear combination of $\omega_1$ and
$\omega_2$ with definite sign. This result improves previous knwon results. Furthermore, if $\omega_1(\nu_1a\psi-\nu_2\varphi)\leq0$ for some $\nu_1,\nu_2\geq0$, we provide necessary and sufficient conditions for the non-existence, and the existence and uniqueness of the limit cycles of these differential systems. When one of these mentioned limit cycles exists it is hyperbolic and surrounds the origin.
file: HuaLiaLli2017.preprint.pdf-b7adbcb909f90cba27bdf6e7ce2b95b3.pdf


type: Article
aigaionid: 4374
bibtexid: CheLliTan2018
title: Global dynamics of a {S}{D} oscillator
author: Chen, Hebai
author: Llibre, Jaume
author: Tang, Yilei
journal: Nonlinear Dynamics
issn: 0924-090X
year: 2018
volume: 91
number: 3
startpage: 1755
endpage: 1777
doi: 10.1007/s11071-017-3979-y
keywords: averaging method
keywords: Bogdanov-Takens bifurcation
keywords: homoclinic loop
keywords: Hopf bifurcation
keywords: limit cycles
keywords: SD oscillator
abstract: In this paper we derive the global bifurcation diagrams of a SD oscillator which exhibits both smooth and discontinuous dynamics depending on the value of a parameter $a$. We research all possible bifurcations of this system, including Pitchfork bifurcation, degenerate Hopf bifurcation, Homoclinic bifurcation, Double limit cycle bifurcation, Bautin bifurcation and Bogdanov-Takens bifurcation. Besides we prove that the system has at most five limit cycles. At last, we give all numerical phase portraits to illustrate our results.
file: CheLliTan2016.Preprint.pdf-f0641ee91ac7ae20adb016855d22a96e.pdf


type: Article
aigaionid: 4391
bibtexid: LliMarVid2018
title: Linear type centers of polynomial {H}amiltonian systems with nonlinearities of degree 4 symmetric with respect to the y-axis
author: Llibre, Jaume
author: Martinez Mancilla, Yohanna Paulina
author: Vidal, Claudio
journal: Discrete and Continuous Dynamical Systems. Series B
issn: 1531-3492
year: 2018
volume: 23
number: 2
startpage: 887
endpage: 912
doi: 10.3934/dcdsb.2018047
keywords: Hamiltonian systems
keywords: linear type centers
keywords: phase portraits
keywords: Polynomial vector fields
keywords: quartic polynomial
abstract: We provide normal forms and the phase portraits in the Poincar\'{e} disk for all the linear type centers of polynomial Hamiltonian systems with nonlinearities of degree $4$ symmetric with respect to the $y$-axis.
file: LliMarVid2016.Preprint.pdf-c66f6fd98fedcf14a159a6dfa23e364c.pdf


type: Article
aigaionid: 4405
bibtexid: LliYu2018a
title: {N}o periodic orbits in the {B}ianchi models {B}
author: Llibre, Jaume
author: Yu, Jiang
journal: Journal of Geometry and Physics
issn: 0393-0440
year: 2018
volume: 128
startpage: 32
endpage: 37
doi: 10.1016/j.geomphys.2018.01.026
keywords: Bianchi cosmological models
keywords: periodic orbit
abstract: In this paper we prove that the Bianchi models B have no periodic solutions.
file: LliYu2016.preprint.pdf-f4b2b7daea019dfc6e9e88c69e26e2ff.pdf


type: Article
aigaionid: 4488
bibtexid: LliVal2018a
title: Global phase portraits for the {A}bel quadratic polynomial differential equations of second kind with {Z}_2-symmetries
author: Llibre, Jaume
author: Valls, Clàudia
journal: Canadian Mathematical Bulletin
issn: 1496-4287
year: 2018
volume: 61
number: 1
startpage: 149
endpage: 165
doi: 10.4153/CMB-2017-026-6
keywords: Abel polynomial differential systems of the second kind
keywords: Phase portrait
keywords: vector fields
abstract: We provide normal forms and the global phase portraits in the Poincar\'e disk for all Abel quadratic polynomial differential equations of the second kind with $\Z_2$-symmetries.
file: LliVal2016g.preprint.pdf-1ef52b98d5c824919a5e18624dd0afe9.pdf


type: Article
aigaionid: 4514
bibtexid: CorCorRob2018
title: A Four-Body Convex Central Configuration with Perpendicular Diagonals Is Necessarily a Kite
author: Corbera, Montserrat
author: Cors, Josep Maria
author: Roberts, Gareth E.
journal: Qualitative Theory of Dynamical Systems
issn: 1575-5460
year: 2018
volume: 17
number: 2
startpage: 367
endpage: 374
doi: 10.1007/s12346-017-0238-z
keywords: Central configuration
keywords: n-body problem
keywords: n-vortex problem
abstract: We prove that any four-body convex central configuration with perpendicular diagonals must be a kite configuration. The result extends to general power-law potential functions, including the planar four-vortex problem.
file: CorCorRob2016.preprint.pdf-c3d73c0db6179dab381eb59d8a5ec1ca.pdf


type: Article
aigaionid: 4518
bibtexid: LliVal2018d
title: Algebraic limit cycles for quadratic polynomial differential systems
author: Llibre, Jaume
author: Valls, Clàudia
journal: Discrete and Continuous Dynamical Systems. Series B
issn: 1531-3492
year: 2018
volume: 23
number: 6
startpage: 2475
endpage: 2485
doi: 10.3934/dcdsb.2018070
keywords: Algebraic limit cycles
keywords: quadratic polynomial differential system
keywords: quadratic polynomial vector field
abstract: We prove that for a quadratic polynomial differential system having three pairs of diametrally opposite equilibrium points at infinity that are positively rationally independent, has at most one algebraic limit cycle. Our result provides a partial positive answer to the following conjecture: Quadratic polynomial differential systems have at most one algebraic limit cycle.
file: LliVal2017b.preprint.pdf-d2643a254bc8f0c9ff5e2b3a9b63f73a.pdf


type: Article
aigaionid: 4521
bibtexid: CimGasMan2018a
title: Parrondo's dynamic paradox for the stability of non-hyperbolic fixed points
author: Cima, Anna
author: Gasull, Armengol
author: Mañosa, Víctor
journal: Discrete and Continuous Dynamical Systems. Series A
issn: 1078-0947
year: 2018
volume: 38
number: 2
startpage: 889
endpage: 904
doi: 10.3934/dcds.2018038
keywords: local and global asymptotic stability
keywords: non-hyperbolic points
keywords: Parrondo's dynamic paradox
keywords: Periodic discrete dynamical systems
abstract: We show that for periodic non-autonomous discrete dynamical systems, even when a common fixed point for each of the autonomous associated dynamical systems is repeller, this fixed point can became a local attractor for the whole system, giving rise to a Parrondo's dynamic type paradox.
file: CimGasMan2017.preprint.pdf-01bc723879bbd5dee15cad57379ba303.pdf


type: Article
aigaionid: 4398
bibtexid: ManRojVil2018
title: Analytic tools to bound the criticality at the outer boundary of the period annulus
author: Mañosas, Francesc
author: Rojas, David
author: Villadelprat, Jordi
journal: Journal of Dynamics and Differential Equations
issn: 1572-9222
year: 2018
volume: 30
number: 3
startpage: 883
endpage: 909
doi: 10.1007/s10884-016-9559-x
keywords: Bifurcation
keywords: Center
keywords: Chebyshev system
keywords: critical periodic orbit
keywords: criticality
keywords: Period function
abstract: In this paper we consider planar potential differential systems and we study the bifurcation of critical periodic orbits from the outer boundary of the period annulus of a center. In the literature the usual approach to tackle this problem is to obtain a uniform asymptotic expansion of the period function near the outer boundary. The novelty in the present paper is that we directly embed the derivative of the period function into a collection of functions that form a Chebyshev system near the outer boundary. We obtain in this way explicit sufficient conditions in order that at most n 0 critical periodic orbits bifurcate from the outer boundary. These theoretical results are then applied to study the bifurcation diagram of the period function of the family x ̈ = xp − xq , p, q ∈ R with p > q.
file: ManRojVil2016b.preprint.pdf-537061e47e47c69a8631ec0524e9dc83.pdf


type: Article
aigaionid: 4424
bibtexid: LliLopMor2018
title: Limit cycles bifurcating from the periodic orbits of the weight-homogeneous polynomial centers of weight-degree 3
author: Llibre, Jaume
author: Lopes, Bruno D.
author: de Moraes, Jaime R.
journal: Electronic Journal of Differential Equations
issn: 1072-6691
year: 2018
number: 118
startpage: 1
endpage: 14
keywords: averaging method
keywords: limit cycles
keywords: Polinomial vector field
keywords: weight-homogeneous differential system
abstract: In this paper we obtain two explicit polynomials, whose simple positive real roots provide the limit cycles which bifurcate from the periodic orbits of a family of polynomial differential centers of order 5, when this family is perturbed inside the class of all polynomial differential systems of order 5, whose average function of first order is not zero. Then the maximum number of limit cycles that bifurcate from these periodic orbits is 6 and it is reached. The family of centers studied completes the study about the limit cycles which can bifurcate from the periodic orbits of all centers of the weight--homogeneous polynomial differential systems of weight--degree 3, when we perturb them inside the class of all polynomial differential systems having the same degree, and whose
average function of first order is not zero.
file: LliLopMor2016a.preprint.pdf-a340c8f1906a1d6f91af08a91e570f36.pdf


type: Article
aigaionid: 4434
bibtexid: GarLliMaz2018
title: On the multiple zeros of a real analytic function with applications to the averaging theory of differential equations
author: García, Isaac A.
author: Llibre, Jaume
author: Maza, Susanna
journal: Nonlinearity
issn: 1361-6544
year: 2018
volume: 31
number: 6
startpage: 2666
endpage: 2688
doi: 10.1088/1361-6544/aab592
keywords: Averaging theory
keywords: periodic orbit
keywords: Poincaré map
abstract: In this work we improve the classical averaging theory applied to $\lambda$-families of analytic $T$-periodic ordinary differential equations in standard form defined on $\mathbb{R}$. First we characterize the set of points $z_0$ in the phase space and the parameters $\lambda$ where $T$-periodic solutions can be produced when we vary a small parameter $\varepsilon$. Second we expand the displacement map in powers of the parameter $\varepsilon$ whose coefficients are the averaged functions. The main contribution consists in analyzing the role that have the multiple zeros $z_0 \in\mathbb{R}$ of the first non-zero averaged function. The outcome is that these multiple zeros can be of two different classes depending on whether the points $(z_0, \lambda)$ belong or not to the analytic set defined by the real variety associated to the ideal generated by the averaged functions in the Noetheriang ring of all the real analytic functions at $(z_0, \lambda)$. Next we are able to bound the maximum number of branches of isolated $T$-periodic solutions that can bifurcate from each multiple zero $z_0$. Sometimes these bounds depend on the cardinalities of minimal bases of the former ideal. Several examples illustrate our results.
file: GarLliMaz2016a.Preprint.pdf-06d68be8d027dbf3034f6a8c209d1cd2.pdf


type: Article
aigaionid: 4522
bibtexid: LliOliVal2018
title: Phase portraits for some symmetric cubic {R}iccati polynomial differential equations
author: Llibre, Jaume
author: Oliveira, Regilene D. S.
author: Valls, Clàudia
journal: Topology and its Applications
issn: 0166-8641
year: 2018
volume: 234
startpage: 220
endpage: 237
doi: 10.1016/j.topol.2017.11.023
keywords: equivariance
keywords: Phase portrait
keywords: reversibility
keywords: Riccati polynomial differential systems
keywords: vector fields
abstract: We classify the topological phase portraits in the Poincaré disc of two classes of symmetric Riccati cubic polynomial differential systems.
file: LliOliVal2017.preprint.pdf-76160d0a1c0770ad51de4c67fe9ac1f9.pdf


type: Article
aigaionid: 4523
bibtexid: CorLliVal2018
title: Periodic orbits of perturbed non-axially symmetric potentials in 1:1:1 and 1:1:2 resonances
author: Corbera, Montserrat
author: Llibre, Jaume
author: Valls, Clàudia
journal: Discrete and Continuous Dynamical Systems. Series B
issn: 1531-3492
year: 2018
volume: 23
number: 6
startpage: 2299
endpage: 2337
doi: 10.3934/dcdsb.2018101
keywords: Averaging theory
keywords: galactic potential
keywords: periodic solution
abstract: We analytically study the Hamiltonian system in $\mathbb{R}^6$ with Hamiltonian $$ H= \frac12 (p_x^2 p_y^2 p_z^2) \frac{1}{2} (\omega_1^2 x^2 \omega_2^2 y^2 \omega_3^2 z^2)
\varepsilon(a z^3 z (b x^2 c y^2)), $$ being $a,b,c\in\mathbb{R}$ with $c\ne 0$, $\varepsilon$ a small parameter, and $\omega_1$, $\omega_2$ and $\omega_3$ the unperturbed frequencies of the oscillations along the $x$, $y$ and $z$ axis, respectively. For $|\varepsilon|>0$ small, using averaging theory of first and second order we find periodic orbits in every positive energy level of $H$ whose frequencies are $\omega_1=\omega_2=\omega_3/2$ and $\omega_1=\omega_2=\omega_3$, respectively (the number of such periodic orbits depends on the values of the parameters $a,b,c$). We also provide the shape of the periodic orbits and their linear stability.
file: CorLliVal2017.preprint.pdf-72721c80094c9a930a5d1cf2c784ca57.pdf


type: Article
aigaionid: 4538
bibtexid: LliSir2018
title: On {L}efschetz periodic point free self-maps
author: Llibre, Jaume
author: Sirvent, Víctor F.
journal: Journal of Fixed Point Theory and Applications
issn: 1661-7746
year: 2018
volume: 30
number: 38
doi: 10.1007/s11784-018-0498-5
keywords: Lefschetz numbers
keywords: Lefschetz zeta function
keywords: periodic point
keywords: product of spheres
keywords: wedge sum of spheres
abstract: We study the periodic point free maps on connected retract of a finite simplicial complex using the Lefschetz numbers. We put special emphasis in the self-maps on the product of spheres and of the wedge sums of spheres.
file: LliSir2017.preprint.pdf-d9f61976f3314c51925e95dc81915994.pdf


type: Article
aigaionid: 4542
bibtexid: LliTon2018
title: The symmetric periodic orbits for the classical helium atom
author: Llibre, Jaume
author: Tonon, Durval J.
journal: Letters in Mathematical Physics
issn: 1573-0530
year: 2018
volume: 108
number: 8
startpage: 1851
endpage: 1871
doi: 10.1007/s11005-018-1056-1
keywords: helium atom
keywords: Poincar\'{e} continuation method
keywords: symmetric periodic orbits
abstract: We analyse the existence of periodic symmetric orbits of the classical helium atom. The results obtained shows that there exists six families of periodic orbits that can be prolonged from a continuum of periodic symmetric orbits. The main technique applied in this study is the continuation method of Poincaré.
file: LliTon2017a.preprint.pdf-cef2474eacf592076f36964061ce9eeb.pdf


type: Article
aigaionid: 4548
bibtexid: CanLli2018
title: Stability of periodic orbits in the averaging theory: Applications to {L}orenz and {T}homas' differential systems
author: Cândido, Murilo R.
author: Llibre, Jaume
journal: International Journal of Bifurcation and Chaos in Applied Sciences and Engineering
issn: 0218-1274
year: 2018
volume: 28
number: 3
startpage: 1830007
doi: 10.1142/S0218127418300070
keywords: Averaging theory
keywords: Circulant systems
keywords: Lorenz
keywords: stability of periodic orbits
keywords: Thomas
abstract: We study the kind of stability of the periodic orbits provided by higher order averaging theory. We apply these results for determining the $k-$hyperbolicity of some periodic orbits of the Lorenz and Thoma's differential system.
file: CanLli2017.preprint.pdf-8bf2a0b70594b29715c1a0aefc96100b.pdf


type: Article
aigaionid: 4528
bibtexid: BarLliVal2018
title: Limit cycles bifurcating from a zero-{H}opf singularity in arbitrary dimension
author: Barreira, Luis
author: Llibre, Jaume
author: Valls, Clàudia
journal: Nonlinear Dynamics
issn: 0924-090X
year: 2018
volume: 92
number: 3
startpage: 1159
endpage: 1166
doi: 10.1007/s11071-018-4115-3
abstract: We study the limit cycles which can bifurcate from a zero--Hopf singularity of a $C^{m 1}$ differential system in $\R^n$, i.e. from a singularity with eigenvalues $\pm b i$ and $n-2$ zeros for $n\ge 3$. If this singularity is at the origin of coordinates and the Taylor expansion of the differential system at the origin without taking into account the linear terms starts with terms of order $m$, from the origin it can bifurcate $s$ limit cycles with $s\in \{ 0,1,\ldots, 2^{n-3}\}$ if $m=2$ (see \cite{LZ}), with $s\in \{ 0,1,\ldots, 3^{n-2}\}$ if $m=3$, with $s\le 6^{n-2}$ if $m=4$, and with $s\le 4\cdot 5^{n-2}$ if $m=5$. Moreover, $s\in \{0,1,2\}$ if $m=4$ and $n=3$, and $s\in \{0,1,2,3,4,5\}$ if $m=5$ and $n=3$. Note that the maximum number of limit cycles bifurcating from this zero--Hopf singularity grows up exponentially with the dimension for $m=2,3$.
file: BarLliVal2017.preprint.pdf-c5ea3bfa2c728380685d7555c892fdf8.pdf


type: Article
aigaionid: 4531
bibtexid: LliMur2018
title: Darboux theory of integrability for real polynomial vector fields on $\mathbb {S}^n$
author: Llibre, Jaume
author: Murza, Adrian
journal: Dynamical Systems. An International Journal
issn: 1468-9367
year: 2018
startpage: 1
endpage: 14
doi: 10.1080/14689367.2017.1420141
keywords: Darboux integrability theory
keywords: invariant meridian
keywords: invariant parallel
keywords: n--dimensional spheres
abstract: This is a survey on the Darboux theory of integrability for
polynomial vector fields, first in $\R^n$ and second in the
$n$-dimensional sphere $\sss^n$. We also provide new results about
the maximum number of invariant parallels and meridians that a polynomial
vector field $\X$ on $\sss^n$ can have in function of its degree.
These results in some sense extend the known result on the maximum
number of hyperplanes that a polynomial vector field $\Y$ in $\R^n$
can have in function of the degree of $\Y$.
file: LliMur2017.preprint.pdf-e1276fd6df078deb983029fef24713b1.pdf


type: Article
aigaionid: 4547
bibtexid: RojVil2018
title: A criticality result for polycycles in a family of quadratic reversible centers
author: Rojas, David
author: Villadelprat, Jordi
journal: Journal of Differential Equations
issn: 0022-0396
year: 2018
volume: 264
number: 11
startpage: 6585
endpage: 6602
doi: 10.1016/j.jde.2018.01.042
keywords: Bifurcation
keywords: Center
keywords: critical periodic orbit
keywords: criticality
keywords: Period function
abstract: We consider the family of dehomogenized LoudÕs centers $X_{\mu}=y(x-1)\partial_x (x Dx^2 Fy^2)\partial_y,$
where $\mu=(D,F)\in\R^2,$ and we study the number of critical periodic orbits that emerge or dissapear from the polycycle at the boundary of the period annulus. This number is defined exactly the same way as the well-known notion of cyclicity of a limit periodic set and we call it criticality. The previous results on the issue for the family $\{X_{\mu},\mu\in\R^2\}$ distinguish between parameters with criticality equal to zero (regular parameters) and those with criticality greater than zero (bifurcation parameters). A challenging problem not tackled so far is the computation of the criticality of the bifurcation parameters, which form a set $\Gamma_{B}$ of codimension 1 in $\R^2$. In the present paper we succeed in proving that a subset of $\Gamma_{B}$ has criticality equal to one.
file: RojVil2017.preprint.pdf-6e30de8beeaf41bca06cd4e32f3d5024.pdf


type: Article
aigaionid: 4559
bibtexid: LliVal2018g
title: Algebraic limit cycles on quadratic polynomial differential systems
author: Llibre, Jaume
author: Valls, Clàudia
journal: Proceedings of the Edinburgh Mathematical Society
issn: 0013-0915
year: 2018
volume: 61
number: 2
startpage: 499
endpage: 512
doi: 10.1017/S0013091517000244
keywords: Algebraic limit cycles
keywords: quadratic polynomial differential system
keywords: quadratic polynomial vector field
abstract: Algebraic limit cycles in quadratic polynomial differential systems started to be studied in 1958, and few years later the following conjecture appeared: Quadratic polynomial differential systems have at most one algebraic limit cycle.
We prove that for a quadratic polynomial differential system having an invariant algebraic curve with at most one pair of diametrally opposite singular point at infinity, has at most one algebraic limit cycle. Our result provides a partial positive answer to this conjecture.
file: LliVal2017g.preprint.pdf-96e3f03c593c599ca0aab7a6b073e3f4.pdf


type: Article
aigaionid: 4574
bibtexid: BuzLimTor2018
title: Limit cycles via higher order perturbations for some piecewise differential systems
author: Buzzi, Claudio A.
author: Lima, Mauricio Firmino Silva
author: Torregrosa, Joan
journal: Physica D. Nonlinear Phenomena
issn: 0167-2789
year: 2018
volume: 371
startpage: 28
endpage: 47
doi: 10.1016/j.physd.2018.01.007
keywords: Liénard piecewise differential system
keywords: limit cycle in Melnikov higher order perturbation
keywords: non-smooth differential system
abstract: A classical perturbation problem is the polynomial perturbation of the harmonic oscillator, $(x',y')=(-y \varepsilon f(x,y,\varepsilon),x \varepsilon g(x,y,\varepsilon)).$ In this paper we study the limit cycles that bifurcate from the period annulus via piecewise polynomial perturbations in two zones separated by a straight line. We prove that, for polynomial perturbations of degree $n,$ no more than $Nn-1$ limit cycles appear up to a study of order $N$. We also show that this upper bound is reached for orders one and two. Moreover, we study this problem in some classes of piecewise Li\'enard differential systems. When we restrict the analysis to some special class this upper bound never is attained and we show which is this upper bound for higher order perturbation in $\varepsilon$. The Poincar\'e--Pontryagin--Melnikov theory is the main technique used to prove all the results.
file: BuzLimTor2017.preprint.pdf-74f9fdbcd1b3892e5a79ac4bc09d013d.pdf


type: Article
aigaionid: 4576
bibtexid: FerValWiu2018
title: On {D}arboux integrability of {E}delstein's reaction system in $\mathbb {R}^3$
author: Ferragut, Antoni
author: Valls, Clàudia
author: Wiuf, Carsten
journal: Chaos, Solitons and Fractals
issn: 0960-0779
year: 2018
volume: 108
startpage: 129
endpage: 135
doi: 10.1016/j.chaos.2018.01.029
keywords: deficiency theorem
keywords: Exponential factor
keywords: First integral
keywords: multi-stationarity
keywords: polynomial system
keywords: Reaction network
abstract: We consider Edelstein's dynamical system of three reversible reactions in $\mathbb R^3$ and show that it is not Darboux integrable. To do so we characterize its polynomial first integrals, Darboux polynomials and exponential factors.
file: FerValWiu2017.preprint.pdf-df8d0758e0803810ffcaab90a025a79d.pdf


type: Article
aigaionid: 4578
bibtexid: FerGarLliMel2018
title: New central configurations of the $(n 1)$--body problem
author: Fernandes, Antonio Carlos
author: Garcia, Braulio Augusto
author: Llibre, Jaume
author: Mello, Luis Fernando
journal: Journal of Geometry and Physics
issn: 0393-0440
year: 2018
volume: 124
startpage: 199
endpage: 207
doi: 10.1016/j.geomphys.2017.11.003
keywords: $(n 1)$--body problem
keywords: Celestial Mechanics
keywords: Central configuration
abstract: In this article we study central configurations of the $(n 1)$--body problem. For the planar $(n 1)$--body problem we study central configurations performed by $n \geq 2$ bodies with equal masses at the vertices of a regular $n$--gon and one body with null mass. We also study spatial central configurations considering $n$ bodies with equal masses at the vertices of a regular polyhedron and one body with null mass.
file: FerGarLliMel2017.pdf-ba095af5a51f188235ebbb74fd9f089c.pdf


type: Article
aigaionid: 4590
bibtexid: DiaLliVal2018
title: Polynomial {H}amiltonian systems of degree 3 with symmetric nilpotent centers
author: Dias, Fabio Scalco
author: Llibre, Jaume
author: Valls, Clàudia
journal: Mathematics and Computers in Simulation
issn: 0378-4754
year: 2018
volume: 144
startpage: 60
endpage: 77
doi: 10.1016/j.matcom.2017.06.002
keywords: Nilpotent center
keywords: Phase portrait
keywords: Poincaré compactification
keywords: polynomial Hamiltonian systems
abstract: We provide normal forms and the global phase portraits in the Poincaré disk for all Hamiltonian planar polynomial vector fields of degree 3 symmetric with respect to the $x$-axis having a nilpotent center at the origin.
file: DiaLliVal2018.Preprint.pdf-2863f40a6c46a690f34d3d3bb2484327.pdf


type: Article
aigaionid: 4591
bibtexid: ArtLliVal2018
title: Dynamics of the {H}iggins-{S}elkov and {S}elkov systems
author: Artés, Joan Carles
author: Llibre, Jaume
author: Valls, Clàudia
journal: Chaos, Solitons and Fractals
issn: 0960-0779
year: 2018
volume: 114
startpage: 145
endpage: 150
doi: 10.1016/j.chaos.2018.07.007
keywords: Higgins-Selkov system
keywords: Phase portrait
keywords: Poincaré compactification
keywords: Selkov system
abstract: We describe the global dynamics in the Poincar\'e disc of the Higgins--Selkov model \begin{equation*} x'= k_0 -k_1 x y^2, \quad y'= -k_2 y k_1 x y^2, \end{equation*} where $k_0,k_1,k_2$ are positive parameters, and of the Selkov model
\begin{equation*} x'= - x a y x^2 y, \quad y'= b - a y - x^2 y, \end{equation*} where $a,b$ are positive parameters.
file: ArtLliVal2017.preprint.pdf-a25fc1e8a7b05d28abda8c807be68ed8.pdf


type: Article
aigaionid: 4575
bibtexid: CruTor2018
title: Simultaneous bifurcation of limit cycles from a cubic piecewise center with two period annuli
author: da Cruz, Leonardo Pereira Costa
author: Torregrosa, Joan
journal: Journal of Mathematical Analysis and Applications
issn: 0022-247X
year: 2018
volume: 461
startpage: 248
endpage: 272
doi: 10.1016/j.jmaa.2017.12.072
keywords: limit cycles
keywords: Piecewise vector field
keywords: Simultaneous bifurcation
keywords: Zeros of Abelian integrals
abstract: We study the number of periodic orbits that bifurcate from a cubic polynomial vector field having two period annuli via piecewise perturbations. The cubic planar system $(x',y')=-y((x-1)^2 y^2),x((x-1)^2 y^2)$ has simultaneously a center at the origin and at infinity. We study, up to first order averaging analysis, the bifurcation of periodic orbits from the two period annuli first separately and second simultaneously. This problem is an generalization of \cite{PerTor2014} to the piecewise systems class. When the polynomial perturbation has degree $n$, we prove that the inner and outer Abelian integrals are rational functions and we provide an upper bound for the number of zeros. When the perturbation is cubic, the same degree than the unperturbed vector field, the maximum number of limit cycles, up to first order perturbation, from the inner and outer annuli is 9 and 8, respectively. But, when the simultaneous bifurcation problem is considered, 12 limit cycles exist. These limit cycles appear in three type of configurations: (9,3), (6,6) and (4,8). In the non-piecewise scenario only 5 limit cycles were found.
file: CruTor2017.Preprint.pdf-81ed6836b6e822e28ce0bc04148384ae.pdf


type: Article
aigaionid: 4589
bibtexid: LliTei2018
title: Piecewise linear differential systems with only centers can create limit cycles?
author: Llibre, Jaume
author: Teixeira, Marco Antonio
journal: Nonlinear Dynamics
issn: 0924-090X
year: 2018
volume: 91
number: 1
startpage: 249
endpage: 255
doi: 10.1007/s11071-017-3866-6
keywords: continuous piecewise linear differential system
keywords: discontinuous piecewise differential systems
keywords: First integral
keywords: limit cycles
keywords: Linear centers
abstract: In this article, we study the continuous and discontinuous planar piecewise differential systems formed only by linear centers separated by one or two parallel straight lines. When these piecewise differential systems are continuous, they have no limit cycles. Also if they are discontinuous separated by a unique straight line, they do not have limit cycles. But when the piecewise differential systems are discontinuous separated two parallel straight lines, we show that they can have at most one limit cycle, and that there exist such systems with one limit cycle.
file: LliTei2017b.preprint.pdf-0ad97dd83da0ea62e1fd6f35be61c0c0.pdf


type: Article
aigaionid: 4604
bibtexid: BuzGasTor2018
title: Algebraic limit cycles in piecewise linear differential systems
author: Buzzi, Claudio A.
author: Gasull, Armengol
author: Torregrosa, Joan
journal: International Journal of Bifurcation and Chaos in Applied Sciences and Engineering
issn: 0218-1274
year: 2018
volume: 28
number: 3
startpage: 1850039
doi: 10.1142/S0218127418500396
keywords: Algebraic limit cycles
keywords: hyperbolic and double limit cycle
keywords: non-smooth differential system
keywords: Piecewise linear systems
keywords: saddle-node bifurcation
abstract: This paper is devoted to study the algebraic limit cycles of planar piecewise linear differential systems. In particular we present examples exhibiting two explicit hyperbolic algebraic limit cycles, as well as some 1-parameter families with a saddle-node bifurcation of algebraic limit cycles. We also show that all degrees for algebraic limit cycles are allowed.
file: BuzGasTor2018.Preprint.pdf-76638afc6c3be306e1c3a48442386e47.pdf


type: Article
aigaionid: 4610
bibtexid: HanLliYan2018
title: On uniqueness of limit cycles in general {B}ogdanov-{T}akens bifurcation
author: Han, Maoan
author: Llibre, Jaume
author: Yang, Junmin
journal: International Journal of Bifurcation and Chaos in Applied Sciences and Engineering
issn: 0218-1274
year: 2018
volume: 28
number: 9
startpage: 1850115
doi: 10.1142/S0218127418501158
keywords: Bodganov-Takens bifurcation
abstract: In this paper we present a complete study to the well-known Bogdanov-Takens bifurcation and give a rigorous proof for the uniqueness of limit cycles.
file: HanLliYan2017.preprint.pdf-37647794c2cee7c4b07ed2db707d63a5.pdf


type: Article
aigaionid: 4637
bibtexid: OllRodSol2018
title: Ejection-collision orbits in the {R}{T}{B}{P}
author: Ollé, Mercè
author: Rodríguez, Òscar
author: Soler, Jaume
journal: Communications in Nonlinear Science and Numerical Simulation
issn: 1007-5704
year: 2018
volume: 55
startpage: 298
endpage: 315
doi: 10.1016/j.cnsns.2017.07.013
keywords: bifurcations
keywords: Ejection-collision orbits
keywords: invariant manifolds
keywords: regularization
abstract: In this paper we analyse the ejection-collision (EC) orbits of the planar restricted three body problem. Being μ∈(0, 0.5] the mass parameter, and taking the big (small) primary with mass 1 − μ (μ), an EC orbit will be an orbit that ejects from the big primary, does an excursion and collides with it. As it is well known, for any value of the mass parameter μ∈(0, 0.5] and sufficiently restricted Hill regions (that is, for big enough values of the Jacobi constant C), there are exactly four EC orbits. We check their existence and extend numerically these four orbits for μ∈(0, 0.5] and for smaller values of the Jacobi constant. We introduce the concept of n-ejection-collision orbits (n-EC orbits) and we explore them numerically for μ∈(0, 0.5] and values of the Jacobi constant such that the Hill bounded possible region of motion contains the big primary and does not contain the small one. We study the cases 1≤n≤10 and we analyse the continuation of families of such n-EC orbits, varying the energy, as well as the bifurcations that appear.
file: OllRodSol2018.preprint.pdf-18d6c8e4be63ed1164acbd5bd48f896a.pdf


type: Article
aigaionid: 4615
bibtexid: CenLliZha2018
title: Periodic solutions and their stability of some higher-order positively homogenous differential equations
author: Cen, Xiuli
author: Llibre, Jaume
author: Zhang, Meirong
journal: Chaos, Solitons and Fractals
issn: 0960-0779
year: 2018
volume: 106
startpage: 285
endpage: 288
doi: 10.1016/j.chaos.2017.11.032
keywords: $m$-Order differential equation
keywords: Averaging theory
keywords: periodic solution
keywords: Stability
abstract: In the present paper we study periodic solutions and their stability of the $m$-order differential equations of the form $$ x^{(m)} f_n(x) = \mu h(t), $$ where the integers $m, n\geq2$, $f_n(x)= \da x^n$ or $\da |x|^n$ with $\da=\pm 1$, and $h(t)$ is a continuous $T$-periodic function of non-zero average, and $\mu$ is a positive small parameter. By using the averaging theory, we will give the existence of $T$-periodic solutions. Moreover, the instability and the linear stability of these periodic solutions will be obtained.
file: CenLliZha2018.preprint.pdf-c3a3054b33d1959025b4998e7a6bfa4c.pdf


type: Article
aigaionid: 4631
bibtexid: OrtRoj2018
title: A proof of {B}ertrand’s theorem using the theory of isochronous potentials
author: Ortega, Rafael
author: Rojas, David
journal: Journal of Dynamics and Differential Equations
issn: 1572-9222
year: 2018
doi: 10.1007/s10884-018-9676-9
keywords: Bertrand’s theorem
keywords: Isochronicity
keywords: potential center
abstract: We give an alternative proof for the celebrated Bertrand’s theorem as a corollary of the isochronicity of a certain family of centers.
file: OrtRoj2018.preprint.pdf-fbb8d5c5a50d74f44e6d6b0c33d26bc6.pdf


type: Article
aigaionid: 4633
bibtexid: GasLloMan2018
title: Periodic points of a {L}anden transformation
author: Gasull, Armengol
author: Llorens, Mireia
author: Mañosa, Víctor
journal: Communications in Nonlinear Science and Numerical Simulation
issn: 1007-5704
year: 2018
volume: 64
startpage: 232
endpage: 245
doi: 10.1016/j.cnsns.2018.04.020
keywords: Landen transformation
keywords: periodic points
keywords: Poincaré-Miranda theorem
abstract: We prove the existence of 3-periodic orbits in a dynamical system associated to a Landen transformation previously studied by Boros, Chamberland and Moll, disproving a conjecture on the dynamics of this planar map introduced by the latter author. To this end we present a systematic methodology to determine and locate analytically isolated periodic points of algebraic maps. This approach can be useful to study other discrete dynamical systems with algebraic nature. Complementary results on the dynamics of the map associated with the Landen transformation are also presented.
file: GasLloMan2018.preprint.pdf-2db49e7b3e3a5ee24a8af8bbc6a80d8c.pdf


type: Article
aigaionid: 4638
bibtexid: JuhSal2018
title: Tuning the overlap and the cross-layer correlations in two-layer networks: application to an {S}{I}{R} model with awareness dissemination
author: Juher, David
author: Saldaña, Joan
journal: Physical Review E
issn: 2470-0045
year: 2018
volume: 97
number: 3
startpage: 032303
doi: 10.1103/PhysRevE.97.032303
abstract: We study the properties of the potential overlap between two networks $A,B$ sharing the same set of $N$ nodes (a two-layer network) whose respective degree distributions $p_A(k), p_B(k)$ are given. Defining the overlap coefficient $\alpha$ as the Jaccard index, we prove that $\alpha$ is very close to 0 when $A$ and $B$ are random and independently generated. We derive an upper bound $\alpha_M$ for the maximum overlap coefficient permitted in terms of $p_A(k)$, $p_B(k)$ and $N$. Then we present an algorithm based on cross-rewiring of links to obtain a two-layer network with any prescribed $\alpha$ inside the range $(0,\alpha_M)$. A refined version of the algorithm allows us to minimize the cross-layer correlations that unavoidably appear for values of $\alpha$ beyond a critical overlap $\alpha_c<\alpha_M$. Finally, we present a very simple example of an SIR epidemic model with information dissemination and use the algorithms to determine the impact of the overlap on the final outbreak size predicted by the model.
file: JuhSal2018.preprint.pdf-54df9d825085c21c83f94488b485e532.pdf


type: Article
aigaionid: 4641
bibtexid: AcoLazMorPan2018
title: Differential {G}alois theory and non-integrability of planar polynomial vector fields
author: Acosta-Humánez, Primitivo B.
author: Lázaro, José Tomás
author: Morales-Ruiz, Juan J.
author: Pantazi, Chara
journal: Journal of Differential Equations
issn: 0022-0396
year: 2018
volume: 264
number: 12
startpage: 7183
endpage: 7212
doi: 10.1016/j.jde.2018.02.016
abstract: We study a necessary condition for the integrability of the polynomials vector fields in the plane by means of the differential Galois Theory. More concretely, by means of the variational equations around a particular solution it is obtained a necessary condition for the existence of a rational first integral. The method is systematic starting with the first order variational equation. We illustrate this result with several families of examples. A key point is to check whether a suitable primitive is elementary or not. Using a theorem by Liouville, the problem is equivalent to the existence of a rational solution of a certain first order linear equation, the Risch equation. This is a classical problem studied by Risch in 1969, and the solution is given by the “Risch algorithm”. In this way we point out the connection of the non integrability with some higher transcendent functions, like the error function.
file: AcoLazMorPan2018.preprint.pdf-d62348d62843b9899c8378c02ff51781.pdf


type: Article
aigaionid: 4657
bibtexid: CanLli2018a
title: Zero--Hopf bifurcations in 3-dimensional differential systems with no equilibria
author: Cândido, Murilo R.
author: Llibre, Jaume
journal: Mathematics and Computers in Simulation
issn: 0378-4754
year: 2018
volume: 151
startpage: 54
endpage: 76
doi: 10.1016/j.matcom.2018.03.008
keywords: Averaging theory
keywords: Periodic solutions
keywords: quadratic polynomial differential system
keywords: Zero-Hopf bifurcation.
abstract: We use averaging theory for studying the Hopf and zero--Hopf bifurcations in some chaotic differential systems. These differential systems have a chaotic attractor and no equilibria. Numerically we show the relation between the existence of the periodic solutions studied in these systems and their chaotic attractors.
file: CanLli2018a.preprint.pdf-1a8d9e6ed827b7e6dbd54f293d336ae5.pdf


type: Article
aigaionid: 4687
bibtexid: CanLli2018b
title: Periodic Orbits Bifurcating from a Nonisolated Zero-{H}opf Equilibrium of three-dimensional Differential Systems Revisited
author: Cândido, Murilo R.
author: Llibre, Jaume
journal: International Journal of Bifurcation and Chaos in Applied Sciences and Engineering
issn: 0218-1274
year: 2018
volume: 28
number: 5
startpage: 1850058
doi: 10.1142/S021812741850058X
keywords: Averaging theory
keywords: Periodic solutions
keywords: Polynomial differential systems
keywords: zero-Hopf bifurcation
keywords: zero-Hopf equilibrium
abstract: In this paper, we study the periodic solutions bifurcating from a nonisolated zero–Hopf equilib- rium in a polynomial differential system of degree two in R3. More specifically, we use recent results of averaging theory to improve the conditions for the existence of one or two periodic solutions bifurcating from such a zero–Hopf equilibrium. This new result is applied for studying the periodic solutions of differential systems in R3 having n-scroll chaotic attractors.
file: CanLli2018b.Preprint.pdf-d157c2527fcdb537c8be5bf26e369233.pdf


type: Article
aigaionid: 4709
bibtexid: Can2018a
title: Rational maps with {F}atou components of arbitrarily large connectivity
author: Canela, Jordi
journal: Journal of Mathematical Analysis and Applications
issn: 0022-247X
year: 2018
volume: 462
startpage: 35
endpage: 56
doi: 10.1016/j.jmaa.2018.01.061
abstract: We study the family of singular perturbations of Blaschke products \linebreak $B_{a,\lambda}(z)=z^3\frac{z-a}{1-\overline{a}z} \frac{\lambda}{z^2}$. We analyse how the connectivity of the Fatou components varies as we move continuously the parameter $\lambda$. We prove that all possible escaping configurations of the critical point $c_-(a,\lambda)$ take place within the parameter space.
In particular, we prove that there are maps $B_{a,\lambda}$ which have Fatou components of arbitrarily large finite connectivity within their dynamical planes.
file: Can2018.Preprint.pdf-3a7e19115b826ed6c1939af0b18833be.pdf


type: Article
aigaionid: 4710
bibtexid: CamCanVin2018
title: Convergence regions for the {C}hebyshev--{H}alley family
author: Campos, Beatriz
author: Canela, Jordi
author: Vindel, Pura
journal: Communications in Nonlinear Science and Numerical Simulation
issn: 1007-5704
year: 2018
volume: 56
startpage: 508
endpage: 525
doi: 10.1016/j.cnsns.2017.08.024
abstract: In this paper, we study the dynamical behaviour of the Chebyshev--Halley family applied on a family of degree $n$ polynomials. For $n=2$ we bound the set of parameters for which the iterative methods have convergence regions which do not correspond to the basins of attraction of the roots. We also study the dynamics of indifferent fixed points on the boundary of the regions of parameters with bad behaviour. Finally, we provide a numerical study on the boundedness of the regions of parameters with bad behaviour for the family of degree $n$ polynomials.
file: CamCanVin2018.Preprint.pdf-8165ca500f1a1584ffad98d32e2e3168.pdf


type: Article
aigaionid: 4619
bibtexid: GasMan2019
title: Subseries and signed series
author: Gasull, Armengol
author: Mañosas, Francesc
journal: Communications on Pure & Applied Analysis
issn: 1553-5258
year: 2019
volume: 18
number: 1
startpage: 479
endpage: 492
doi: 10.3934/cpaa.2019024
keywords: divergent series
keywords: Harmonic series
keywords: random series
keywords: signed sums
keywords: subsums
abstract: For any positive decreasing to zero sequence $a_n$ such
that $\sum a_n$ diverges we consider the related series $\sum
k_na_n$ and $\sum j_na_n.$ Here, $k_n$ and $j_n$ are real
sequences such that $k_n\in\{0,1\}$ and $j_n\in\{-1,1\}.$ We study their convergence and characterize it in terms of the density of 1's in the sequences $k_n$ and $j_n.$ We extend our results to series $\sum m_na_n,$ with $m_n\in\{-1,0,1\}$ and apply them to study some associated random series.
file: GasMan2017.preprint.pdf-72eac3088022b515405dbc6d691387bd.pdf


type: Article
aigaionid: 4688
bibtexid: CheLli2019
title: Limit cycles of a second-order differential equation
author: Chen, Ting
author: Llibre, Jaume
journal: Applied Mathematics Letters. An International Journal of Rapid Publication
issn: 0893-9659
year: 2019
volume: 88
startpage: 111
endpage: 117
doi: 10.1016/j.aml.2018.08.015
keywords: Averaging theory
keywords: limit cycle
keywords: Mathieu-Duffing type
abstract: We provide an upper for the maximum number of limit cycles bifurcating from the periodic solutions of $\ddot{x} x=0$, when we perturb this system as follows \ \ddot{x} \varepsilon(1 \cos^m \theta)Q(x,y) x=0, \] where $\varepsilon>0$ is a small parameter, $m$ is an arbitrary non-negative integer, $Q(x,y)$ is a polynomial of degree $n$ and $\theta=\arctan(y/x)$. The main tool used for proving our results is the averaging theory.
file: CheLli2018b.preprint.pdf-1c960ecb719c4481e53aeb90bcc12eba.pdf





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