{"title":"Analysis of the Hopf bifurcation in a Diffusive Gierer-Meinhardt Model","authors":"Rasoul Asheghi","doi":"10.12775/tmna.2022.050","DOIUrl":"https://doi.org/10.12775/tmna.2022.050","url":null,"abstract":"In this work, we consider an activator-inhibitor system, known as the Gierer-Meinhardt model. Using the linear stability analysis at the unique positive equilibrium, we derive the conditions of the Hopf bifurcation. We compute the normal form of this bifurcation up to the third degree and obtain the direction of the Hopf bifurcation. Finally, we provide numerical simulations to illustrate the theoretical results of this paper. In this study, we will use the technique of normal form and center manifold theorem.","PeriodicalId":23130,"journal":{"name":"Topological Methods in Nonlinear Analysis","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135966918","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Topological complexity of $S^3/Q_8$ as fibrewise L-S category","authors":"Norio Iwase, Yuya Miyata","doi":"10.12775/tmna.2022.068","DOIUrl":"https://doi.org/10.12775/tmna.2022.068","url":null,"abstract":"In 2010, M. Sakai and the first author showed that the topological complexity of a space $X$ coincides with the fibrewise unpointed L-S category of a pointed fibrewise space $proj_{1} colon X times X to X$ with the diagonal map $Delta colon X to X times X$ as its section. In this paper, we describe our algorithm how to determine the fibrewise L-S category or the Topological Complexity of a topological spherical space form. Especially, for $S^3/Q_8$ where $Q_8$ is the quaternion group, we write a python code to realise the algorithm to determine its Topological Complexity.","PeriodicalId":23130,"journal":{"name":"Topological Methods in Nonlinear Analysis","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135966915","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Solutions to degenerative generalized quasilinear Schrödinger equations involving vanishing potentials and critical exponent","authors":"Yong Huang, Zhouxin Li, X. Yuan","doi":"10.12775/tmna.2022.045","DOIUrl":"https://doi.org/10.12775/tmna.2022.045","url":null,"abstract":"In this paper, a class of degenerative quasilinear Schrödinger equations with\u0000 vanishing potentials and critical Sobolev exponents is considered.\u0000The main operator involved in these equations is not strictly elliptic. Under suitable conditions, the existence of nontrivial solutions to the equations is obtained\u0000by employing variational methods and the decay rate of the solutions is established.","PeriodicalId":23130,"journal":{"name":"Topological Methods in Nonlinear Analysis","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2023-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47537449","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Hilbert and Poincaré problems for semi-linear equations in rectifiable domains","authors":"V. Ryazanov","doi":"10.12775/tmna.2022.044","DOIUrl":"https://doi.org/10.12775/tmna.2022.044","url":null,"abstract":"The study of the boundary value problem with arbitrary\u0000measurable data originated in the dissertation of Luzin where\u0000he investigated the Dirichlet problem for harmonic functions in the unit\u0000disk.\u0000Recently, in cite{R7}, we studied the Hilbert, Poincaré and Neumann\u0000boundary value problems with arbitrary measurable data for\u0000generalized analytic and generalized harmonic functions and provided\u0000applications to relevant problems in mathematical physics.\u0000The present paper is devoted to the study of the boundary value\u0000problem with arbitrary measurable boundary data in a domain with\u0000rectifiable boundary corresponding to semi-linear equation with\u0000suitable nonlinear source. We construct a completely continuous\u0000operator and generate nonclassical solutions to the Hilbert and\u0000Poincaré boundary value problems with arbitrary measurable data for\u0000Vekua type and Poisson equations, respectively. Based on that, we\u0000prove the existence of solutions of the Hilbert boundary value\u0000problem for the nonlinear Vekua type equation with arbitrary\u0000measurable data in a domain with rectifiable boundary.\u0000It is necessary to point out that our approach differs from the\u0000classical variational approach in PDE as it is based on the\u0000geometric interpretation of boundary values as angular (along\u0000non-tangential paths) limits.\u0000The latter makes it possible to also obtain a theorem on the\u0000boundary value problem for directional derivatives,\u0000 and, in\u0000particular, of the Neumann problem with arbitrary measurable\u0000data for the Poisson equation with nonlinear sources in any Jordan\u0000domain with rectifiable boundary.\u0000As a result we arrive at applications to some problems of\u0000mathematical physics.","PeriodicalId":23130,"journal":{"name":"Topological Methods in Nonlinear Analysis","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2023-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47244046","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Existence theory for nabla fractional three-point boundary value problems via continuation methods for contractive maps","authors":"J. Jonnalagadda","doi":"10.12775/tmna.2022.043","DOIUrl":"https://doi.org/10.12775/tmna.2022.043","url":null,"abstract":"In this article, we analyse an $alpha$-th order, $1 < alpha leq 2$, nabla fractional\u0000 three-point boundary value problem (BVP). We construct the Green's function\u0000 associated to this problem and derive a few of its important properties.\u0000We then establish sufficient conditions on existence and uniqueness of solutions\u0000for the corresponding nonlinear BVP using the modern ideas of continuation methods\u0000 for contractive maps. Our results extend recent results on nabla fractional BVPs. Finally, we provide an example to illustrate the applicability of main results.","PeriodicalId":23130,"journal":{"name":"Topological Methods in Nonlinear Analysis","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2023-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46207326","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Existence of saddle-type solutions for a class of quasilinear problems in R^2","authors":"C. O. Alves, Renan J. S. Isneri, P. Montecchiari","doi":"10.12775/tmna.2022.039","DOIUrl":"https://doi.org/10.12775/tmna.2022.039","url":null,"abstract":"The main goal of the present paper is to prove the existence of saddle-type solutions for the following class of quasilinear problems\u0000$$\u0000-Delta_{Phi}u + V'(u)=0quad text{in }mathbb{R}^2,\u0000$$%\u0000where\u0000$$\u0000Delta_{Phi}u=text{div}(phi(|nabla u|)nabla u),\u0000$$%\u0000$Phicolon mathbb{R}rightarrow [0,+infty)$ is an N-function\u0000and the potential $V$ satisfies some technical condition and we have\u0000as an example $ V(t)=Phi(|t^2-1|)$.","PeriodicalId":23130,"journal":{"name":"Topological Methods in Nonlinear Analysis","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2023-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43840733","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Weighted fourth order equation of Kirchhoff type in dimension 4 with non-linear exponential growth","authors":"Rached Jaidane","doi":"10.12775/tmna.2023.005","DOIUrl":"https://doi.org/10.12775/tmna.2023.005","url":null,"abstract":"In this work, we are concerned with the existence of a ground state solution\u0000 for a Kirchhoff weighted problem under boundary Dirichlet condition\u0000 in the unit ball of $mathbb{R}^{4}$.\u0000 The nonlinearities have critical growth in view of Adams'\u0000 inequalities. To prove the existence result, we use Pass Mountain Theorem.\u0000The main difficulty is\u0000the loss of compactness due to the critical exponential growth of the nonlinear\u0000term $f$. The associated energy function does not satisfy\u0000 the condition of compactness. We provide a new condition for growth and we stress its importance\u0000 to check the min-max compactness level.","PeriodicalId":23130,"journal":{"name":"Topological Methods in Nonlinear Analysis","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2023-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46910351","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Halpern-type proximal point algorithm in CAT(0) spaces","authors":"C. C. Okeke","doi":"10.12775/tmna.2022.038","DOIUrl":"https://doi.org/10.12775/tmna.2022.038","url":null,"abstract":"A method which is a combination of the Halpern method and proximal point method\u0000(PPA) is introduced in this paper. It is proved that the sequence of iterates generated by our method converges strongly \u0000to a point which is a common solution to some monotone inclusion problem and fixed point problem in CAT$(0)$ spaces under some appropriate conditions.","PeriodicalId":23130,"journal":{"name":"Topological Methods in Nonlinear Analysis","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2023-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48696183","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Convergence and well-posedness properties of uniformly locally contractive mappings","authors":"S. Reich, A. Zaslavski","doi":"10.12775/tmna.2022.035","DOIUrl":"https://doi.org/10.12775/tmna.2022.035","url":null,"abstract":"In a 1961 paper by E. Rakotch it was shown that a uniformly locally contractive\u0000 mapping has a fixed point. In the present paper we show that for such a mapping,\u0000 the fixed point problem is well posed and that inexact iterates of such a mapping\u0000 converge to its unique fixed point, uniformly on bounded sets. Using the porosity\u0000 notion, we also show that most uniformly locally nonexpansive mappings are, in fact, uniformly locally contractive.","PeriodicalId":23130,"journal":{"name":"Topological Methods in Nonlinear Analysis","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2023-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46706953","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Lower semicontinuity of Kirchhoff-type energy functionals and spectral gaps on (sub)Riemannian manifolds","authors":"Csaba Farkas, S. Kajántó, C. Varga","doi":"10.12775/tmna.2022.034","DOIUrl":"https://doi.org/10.12775/tmna.2022.034","url":null,"abstract":"In this paper we characterize the sequentially weakly lower semicontinuity\u0000of the parameter-depending energy functional associated with the critical Kirchhoff\u0000problem in context of (sub)Riemannian manifolds.\u0000We also present some spectral gap and convexity results.","PeriodicalId":23130,"journal":{"name":"Topological Methods in Nonlinear Analysis","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2023-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44069069","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}