Existence of at most two limit cycles for some non-autonomous differential equations

It is know that the non-autonomous differential equations dx/dt = a(t)+b(t)|x|, where a(t) and b(t) are 1-periodic maps of class C1, have no upper bound for their number of limit cycles (isolated solutions satisfying x(0) = x(1)). We prove that if either a(t) or b(t) does not change sign, then their...

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Bibliographic Details
Authors: Gasull, A.; Zhao, Y.
Format: Article
Status:Accepted version
Publication date:2023
Country:España
Institution:Varias* (Consorci de Biblioteques Universitáries de Catalunya, Centre de Serveis Científics i Acadèmics de Catalunya)
Repository:Recercat. Dipósit de la Recerca de Catalunya
OAI Identifier:oai:recercat.cat:2072/536856
Online Access:http://hdl.handle.net/2072/536856
Access Level:Open access
Keyword:limit cycle
Non-autonomous differential equation
periodic orbit
Description
Summary:It is know that the non-autonomous differential equations dx/dt = a(t)+b(t)|x|, where a(t) and b(t) are 1-periodic maps of class C1, have no upper bound for their number of limit cycles (isolated solutions satisfying x(0) = x(1)). We prove that if either a(t) or b(t) does not change sign, then their maximum number of limit cycles is two, taking into account their multiplicities, and that this upper bound is sharp. We also study all possible configurations of limit cycles. Our result is similar to other ones known for Abel type periodic differential equations although the proofs are quite different. © 2023 American Institute of Mathematical Sciences. All rights reserved.