Francisco Braun , Leonardo Pereira Costa da Cruz , Joan Torregrosa
{"title":"On the number of limit cycles in piecewise planar quadratic differential systems","authors":"Francisco Braun , Leonardo Pereira Costa da Cruz , Joan Torregrosa","doi":"10.1016/j.nonrwa.2024.104124","DOIUrl":"https://doi.org/10.1016/j.nonrwa.2024.104124","url":null,"abstract":"<div><p>We consider piecewise quadratic perturbations of centers of piecewise quadratic systems in two zones determined by a straight line through the origin. By means of expansions of the displacement map, we are able to find isolated zeros of it, without dealing with the unsurprising difficult integrals inherent in the usual averaging approach. We apply this technique to non-smooth perturbations of the four families of isochronous centers of the Loud family, <span><math><msub><mrow><mi>S</mi></mrow><mrow><mn>1</mn></mrow></msub></math></span>, <span><math><msub><mrow><mi>S</mi></mrow><mrow><mn>2</mn></mrow></msub></math></span>, <span><math><msub><mrow><mi>S</mi></mrow><mrow><mn>3</mn></mrow></msub></math></span>, and <span><math><msub><mrow><mi>S</mi></mrow><mrow><mn>4</mn></mrow></msub></math></span>, as well as to non-smooth perturbations of non-smooth centers given by putting different <span><math><msub><mrow><mi>S</mi></mrow><mrow><mi>i</mi></mrow></msub></math></span>’s in each zone. To show the coverage of our approach, we apply its first order, which is equivalent to averaging theory of the first order, in perturbations of the already mentioned centers considering all the straight lines through the origin. Then we apply the second order of our approach to perturbations of the above centers for a specific oblique straight line. Here in order to argue we introduce certain blow-ups in the perturbative parameters. As a consequence of our study, we obtain examples of piecewise quadratic systems with at least 12 limit cycles. By analyzing two previous works of the literature claiming much more limit cycles we found some mistakes in the calculations. Therefore, the best lower bound for the number of limit cycles of a piecewise quadratic system is up to now the 12 limit cycles found in the present paper.</p></div>","PeriodicalId":49745,"journal":{"name":"Nonlinear Analysis-Real World Applications","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2024-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140824129","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Optimal decay estimate and asymptotic profile for solutions to the generalized Zakharov–Kuznetsov–Burgers equation in 2D","authors":"Ikki Fukuda , Hiroyuki Hirayama","doi":"10.1016/j.nonrwa.2024.104130","DOIUrl":"https://doi.org/10.1016/j.nonrwa.2024.104130","url":null,"abstract":"<div><p>We consider the Cauchy problem for the generalized Zakharov–Kuznetsov–Burgers equation in 2D. This is one of the nonlinear dispersive–dissipative equations, which has a spatial anisotropic dissipative term <span><math><mrow><mo>−</mo><mi>μ</mi><msub><mrow><mi>u</mi></mrow><mrow><mi>x</mi><mi>x</mi></mrow></msub></mrow></math></span>. In this paper, we prove that the solution to this problem decays at the rate of <span><math><msup><mrow><mi>t</mi></mrow><mrow><mo>−</mo><mfrac><mrow><mn>3</mn></mrow><mrow><mn>4</mn></mrow></mfrac></mrow></msup></math></span> in the <span><math><msup><mrow><mi>L</mi></mrow><mrow><mi>∞</mi></mrow></msup></math></span>-sense, provided that the initial data <span><math><mrow><msub><mrow><mi>u</mi></mrow><mrow><mn>0</mn></mrow></msub><mrow><mo>(</mo><mi>x</mi><mo>,</mo><mi>y</mi><mo>)</mo></mrow></mrow></math></span> satisfies <span><math><mrow><msub><mrow><mi>u</mi></mrow><mrow><mn>0</mn></mrow></msub><mo>∈</mo><msup><mrow><mi>L</mi></mrow><mrow><mn>1</mn></mrow></msup><mrow><mo>(</mo><msup><mrow><mi>R</mi></mrow><mrow><mn>2</mn></mrow></msup><mo>)</mo></mrow></mrow></math></span> and some appropriate regularity assumptions. Moreover, we investigate the more detailed large time behavior and obtain a lower bound of the <span><math><msup><mrow><mi>L</mi></mrow><mrow><mi>∞</mi></mrow></msup></math></span>-norm of the solution. As a result, we prove that the given decay rate <span><math><msup><mrow><mi>t</mi></mrow><mrow><mo>−</mo><mfrac><mrow><mn>3</mn></mrow><mrow><mn>4</mn></mrow></mfrac></mrow></msup></math></span> of the solution to be optimal. Furthermore, combining the techniques used for the parabolic equations and for the Schr<span><math><mover><mrow><mi>o</mi></mrow><mrow><mo>̈</mo></mrow></mover></math></span>dinger equation, we derive the explicit asymptotic profile for the solution.</p></div>","PeriodicalId":49745,"journal":{"name":"Nonlinear Analysis-Real World Applications","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2024-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140825738","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Spatio-temporal patterns and global bifurcation of a nonlinear cross-diffusion predator–prey model with prey-taxis and double Beddington–DeAngelis functional responses","authors":"Demou Luo , Qiru Wang","doi":"10.1016/j.nonrwa.2024.104133","DOIUrl":"https://doi.org/10.1016/j.nonrwa.2024.104133","url":null,"abstract":"<div><p>The aim of this article is investigating the spatio-temporal patterns of a nonlinear cross-diffusion predator–prey model with prey-taxis and double Beddington–DeAngelis functional responses. First, by utilizing user-friendly version of Crandall–Rabinowitz bifurcation theory as an analytical method, the spatio-temporal patterns of positive steady state are obtained. Then, by regarding the cross-diffusion coefficient <span><math><msub><mrow><mi>d</mi></mrow><mrow><mn>1</mn></mrow></msub></math></span> as a bifurcation parameter, we will derive a bifurcation theorem for the corresponding nonlinear cross-diffusion model. Moreover, by applying spectrum theory, perturbation of simple eigenvalues and linearized stability, it is discovered that the bifurcation solutions possess local stability near the bifurcating point in proper conditions. These theoretical results mean that the cross-diffusion mechanism can create a coexistence environment for the preys and predator under some circumstances. Finally, a numerical example is proposed to verify our results.</p></div>","PeriodicalId":49745,"journal":{"name":"Nonlinear Analysis-Real World Applications","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2024-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140825739","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jean-Christophe Poggiale , Rafael Bravo de la Parra , Ezio Venturino
{"title":"The role of manipulative trophically transmitted parasites in the stability of a predator–prey community","authors":"Jean-Christophe Poggiale , Rafael Bravo de la Parra , Ezio Venturino","doi":"10.1016/j.nonrwa.2024.104123","DOIUrl":"https://doi.org/10.1016/j.nonrwa.2024.104123","url":null,"abstract":"<div><p>In this paper, we are interested in the effect of a trophically transmitted parasite on the structure and dynamics of a resident predator–prey community. The parasite, apart from increasing the mortality rates of its hosts, can also change their physiology or their behaviour, which is known as trait-mediated indirect interaction. We assume that parasite transmission, which entails rapid physiological or behavioural change, is a fast process with respect to the community dynamics, including prey and predator growths and predation. This existence of different time scales allows us to provide analytical results to understand some conditions under which the parasite change the dynamics of the predator–prey community. Thus, we are able to find conditions under which indirect trait-mediated interactions induced by the parasite lead to a coexistence between predators and prey that would not occur in its absence. We also provide conditions, evolutionary deleterious, that ensure the extinction of a predator–prey community that would be viable without parasite intervention. Finally, we show situations in which the action of the parasite destabilizes the predator–prey system without eliminating it, producing oscillations, the mechanism of which is analysed.</p></div>","PeriodicalId":49745,"journal":{"name":"Nonlinear Analysis-Real World Applications","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2024-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1468121824000634/pdfft?md5=c007706a979b3aa387e052c31cc79141&pid=1-s2.0-S1468121824000634-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140816717","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"On a Stokes hemivariational inequality for incompressible fluid flows with damping","authors":"Weimin Han , Hailong Qiu , Liquan Mei","doi":"10.1016/j.nonrwa.2024.104131","DOIUrl":"https://doi.org/10.1016/j.nonrwa.2024.104131","url":null,"abstract":"<div><p>In this paper, a Stokes hemivariational inequality is studied for incompressible fluid flows with the damping effect. The hemivariational inequality feature is caused by the presence of a nonsmooth slip boundary condition of friction type. Well-posedness of the Stokes hemivariational inequality is established through the consideration of a minimization problem. Mixed finite element methods are introduced to solve the Stokes hemivariational inequality and error estimates are derived for the mixed finite element solutions. The error estimates are of optimal order for low-order mixed element pairs under suitable solution regularity assumptions. An efficient iterative algorithm is introduced to solve the mixed finite element system. Numerical results are reported on the performance of the proposed algorithm and the numerical convergence orders of the finite element solutions.</p></div>","PeriodicalId":49745,"journal":{"name":"Nonlinear Analysis-Real World Applications","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2024-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140649212","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Stability and codimension 2 bifurcations in an SIR model with incubation delay","authors":"Tanuja Das, Prashant K. Srivastava","doi":"10.1016/j.nonrwa.2024.104127","DOIUrl":"https://doi.org/10.1016/j.nonrwa.2024.104127","url":null,"abstract":"<div><p>The aim of this paper is to investigate the complex nonlinear dynamics, such as the existence and effect of various types of bifurcations, in an infectious disease model system. An <span><math><mrow><mi>S</mi><mi>I</mi><mi>R</mi></mrow></math></span> delay model that accounts for saturated incidence, saturated treatment, and self-protection in the susceptible population is considered. The model system has a disease free equilibrium, and its local stability is determined by the basic reproduction number for any delay value. The existence of multiple endemic equilibria is obtained, and these equilibria may switch stability due to variation of bifurcation parameters. When incubation delay is zero, Bogdanov–Takens bifurcation occurs, which implies the existence of Hopf bifurcation, saddle–node, and homoclinic bifurcations. Thus, the disease will persist within or on the homoclinic loop and otherwise dies out. We also find the existence of backward bifurcation and forward (transcritical) bifurcation. The delay-induced stability switches are observed due to Hopf bifurcations, leading to endemic bubbles. Incubation delay affects the stability of equilibria when the model system has multiple endemic equilibria, so multi-stability is observed. Due to incubation delay, the two frequency Hopf–Hopf bifurcation and Bogdanov–Takens bifurcation are found. Thus, both codimension 1 and codimension 2 bifurcations in the effect of incubation delay are exhibited in this study. Numerically, we notice that with increasing incubation delay, the endemic equilibrium either changes stability (from stable to unstable or unstable to stable) or remains unstable with different frequencies of oscillations.</p></div>","PeriodicalId":49745,"journal":{"name":"Nonlinear Analysis-Real World Applications","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2024-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140807061","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Long time asymptotics of small mass solutions for a chemotaxis-consumption system involving prescribed signal concentrations on the boundary","authors":"Soo-Oh Yang , Jaewook Ahn","doi":"10.1016/j.nonrwa.2024.104129","DOIUrl":"https://doi.org/10.1016/j.nonrwa.2024.104129","url":null,"abstract":"<div><p>This paper investigates a parabolic–elliptic chemotaxis-consumption system with signal dependent sensitivity <span><math><mrow><mi>χ</mi><mo>=</mo><mi>χ</mi><mrow><mo>(</mo><mi>c</mi><mo>)</mo></mrow></mrow></math></span> under no-flux/Dirichlet boundary conditions. For general <span><math><mi>χ</mi></math></span> which may allow singularities at <span><math><mrow><mi>c</mi><mo>=</mo><mn>0</mn></mrow></math></span>, the global existence and boundedness of radial large data solutions are established in dimensions <span><math><mrow><mi>d</mi><mo>≥</mo><mn>2</mn></mrow></math></span>. In particular, when <span><math><mrow><mi>χ</mi><mrow><mo>(</mo><mi>c</mi><mo>)</mo></mrow><mo>=</mo><mn>1</mn></mrow></math></span>, we also find that the constructed solution converges asymptotically to a nonhomogeneous steady state if the initial mass is small. On the other hand, for the system with <span><math><mrow><mi>χ</mi><mrow><mo>(</mo><mi>c</mi><mo>)</mo></mrow><mo>=</mo><mi>c</mi></mrow></math></span>, a Lyapunov-type inequality is derived. This inequality not only leads to a result on global existence of smooth solutions with non-radial large data in two dimensions but moreover, provides long-time asymptotics of non-radial <span><math><mrow><mo>(</mo><mi>d</mi><mo>=</mo><mn>2</mn><mo>)</mo></mrow></math></span> and radial <span><math><mrow><mo>(</mo><mi>d</mi><mo>≥</mo><mn>2</mn><mo>)</mo></mrow></math></span> solutions at suitably small mass levels.</p></div>","PeriodicalId":49745,"journal":{"name":"Nonlinear Analysis-Real World Applications","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2024-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140649213","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Juan Arratia , Diego Ferraz , Denilson Pereira , Pedro Ubilla
{"title":"Semilinear elliptic problems involving a fast increasing diffusion weight","authors":"Juan Arratia , Diego Ferraz , Denilson Pereira , Pedro Ubilla","doi":"10.1016/j.nonrwa.2024.104128","DOIUrl":"https://doi.org/10.1016/j.nonrwa.2024.104128","url":null,"abstract":"<div><p>In this work we study the existence and multiplicity of positive bounded solutions to a class of problems with a reaction–diffusion equation: <span><span><span><math><mfenced><mrow><mtable><mtr><mtd><mo>−</mo><mtext>div</mtext><mfenced><mrow><mi>K</mi><mrow><mo>(</mo><mi>x</mi><mo>)</mo></mrow><mo>∇</mo><mi>u</mi></mrow></mfenced><mo>=</mo><mi>f</mi><mrow><mo>(</mo><mi>x</mi><mo>,</mo><mi>u</mi><mo>)</mo></mrow></mtd><mtd><mtext>in</mtext></mtd><mtd><msup><mrow><mi>R</mi></mrow><mrow><mi>N</mi></mrow></msup><mo>,</mo></mtd></mtr><mtr><mtd><mi>u</mi><mrow><mo>(</mo><mi>x</mi><mo>)</mo></mrow><mo>→</mo><mn>0</mn></mtd><mtd><mtext>as</mtext></mtd><mtd><mrow><mo>|</mo><mi>x</mi><mo>|</mo></mrow><mo>→</mo><mi>∞</mi><mo>.</mo></mtd></mtr></mtable></mrow></mfenced></math></span></span></span>Using a sublinear hypothesis on the nonlinearity <span><math><mrow><mi>f</mi><mrow><mo>(</mo><mi>x</mi><mo>,</mo><mi>u</mi><mo>)</mo></mrow></mrow></math></span> near the origin, we obtain a solution <span><math><mrow><msub><mrow><mi>u</mi></mrow><mrow><mn>1</mn></mrow></msub><mo>.</mo></mrow></math></span> Furthermore taking <span><math><mrow><mi>K</mi><mrow><mo>(</mo><mi>x</mi><mo>)</mo></mrow><mo>=</mo><msup><mrow><mi>e</mi></mrow><mrow><mi>θ</mi><mrow><mo>(</mo><mi>x</mi><mo>)</mo></mrow></mrow></msup></mrow></math></span> where <span><math><mrow><mi>θ</mi><mrow><mo>(</mo><mi>x</mi><mo>)</mo></mrow></mrow></math></span> satisfies some fast increasing growth conditions, we find via variational methods, a second solution <span><math><msub><mrow><mi>u</mi></mrow><mrow><mn>2</mn></mrow></msub></math></span> in such a way that <span><math><mrow><msub><mrow><mi>u</mi></mrow><mrow><mn>2</mn></mrow></msub><mo>></mo><msub><mrow><mi>u</mi></mrow><mrow><mn>1</mn></mrow></msub><mo>.</mo></mrow></math></span> For this purpose, a new type of compactness is provided for the associated energy functional.</p></div>","PeriodicalId":49745,"journal":{"name":"Nonlinear Analysis-Real World Applications","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2024-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140650481","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Coexistence of two species with intra- and interspecific competition in an unstirred chemostat","authors":"Xuan Bai, Yao Shi, Xiongxiong Bao","doi":"10.1016/j.nonrwa.2024.104125","DOIUrl":"https://doi.org/10.1016/j.nonrwa.2024.104125","url":null,"abstract":"<div><p>In this paper, we study an intra- and interspecific competition system with the different diffusion rates in an unstirred chemostat. Due to the present of the different diffusion rates, the conservation principle for a classical standard chemostat model does not hold here. Firstly, we prove the existence, the uniqueness and asymptotic behaviors of positive solution of the single population system by using the degree theory. Secondly, by the degree theory and standard bifurcation theory, the existence and global structure of the coexistence solutions are investigated. The results show that when the maximum growth rates of two microorganisms with different diffusion abilities are not small, two competing microorganisms will coexist. Finally, numerical simulations are performed to illustrate that the interspecific interference can help the weaker competitor to win in the competition.</p></div>","PeriodicalId":49745,"journal":{"name":"Nonlinear Analysis-Real World Applications","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2024-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140631596","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"The effects of diffusion and advection on the dynamics of a Lotka–Volterra competition system","authors":"Xiao Yan , Hua Nie","doi":"10.1016/j.nonrwa.2024.104126","DOIUrl":"https://doi.org/10.1016/j.nonrwa.2024.104126","url":null,"abstract":"<div><p>This study focuses on a two-species competition-diffusion-advection system, in which two species may have different population dynamics. Using the diffusion rate and advection rate as two varying parameters, we establish a clear classification of the dynamics of this system. It turns out that there is a tradeoff between growth capacity and dispersal strategy driven invasion and coexistence mechanisms. Stronger growth and slower advection are more conducive to the successful invasion of species. Balanced growth and advection are favorable for species coexistence. In addition, species with weak growth and slow advection can coexist with competitive opponents with strong growth and moderate advection. These results show that dispersal strategies and growth capacities are important for determining dynamics.</p></div>","PeriodicalId":49745,"journal":{"name":"Nonlinear Analysis-Real World Applications","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2024-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140631595","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}