Event Type:  SEMINÁRIO 

Event Period:  Jul 28, 2020 a Dec 15, 2022 
About:  
The purpose of this webinar is to maintain contact with researchers from around the world in the specific area of nonlinear analysis, partial differential equations and geometric analysis. The talks will be held mainly on Tuesdays 4p.m. (GMT 3) via Google Meet. Since 2020, we had a total of 42 talks by different researchers from all over the world. Please check our program for details and recordings of these talks. The 2022 season started on march 08. See the program for the confirmed schedule so far. NEXT TALK João Henrique de Andrade (USP  Brazil) 17/05/2022  4p.m. local time (3:00 GMT) Title: Multiplicity of solutions to the multiphasic AllenCahnHilliard system with a small volume constraint on closed parallelizable manifolds Abstract: We prove the existence of multiple solutions to the AllenCahnHilliard (ACH) vectorial equation involving a multiwell (multiphasic) potential with a small volume constraint on a closed parallelizable Riemannian manifold. More precisely, we find a lower bound for the number of solutions depending on some topological invariants of the underlying manifold. The phase transition potential is considered to have a finite set of global minima, where it also vanishes, and a subcritical growth at infinity. Our strategy is to employ the LusternikSchnirelmann and infinitedimensional Morse theories for the vectorial energy functional. To this end, we exploit that the associated ACH energy $\Gamma$converges to the vectorial perimeter for clusters, which combined with some deep theorems from isoperimetric theory yields the suitable set up to apply the photography method. Along the way, the lack of a closed analytic expression for the multiisoperimetric function for clusters imposes a delicate issue. Furthermore, using a transversality theorem, we also show the genericity of the set of metrics for which solutions to our geometric system are nondegenerate. 

Next talks João Henrique de Andrade (USP  Brazil) 17/05/2022  4p.m. local time (3:00 GMT) Title: Multiplicity of solutions to the multiphasic AllenCahnHilliard system with a small volume constraint on closed parallelizable manifolds Abstract: We prove the existence of multiple solutions to the AllenCahnHilliard (ACH) vectorial equation involving a multiwell (multiphasic) potential with a small volume constraint on a closed parallelizable Riemannian manifold. More precisely, we find a lower bound for the number of solutions depending on some topological invariants of the underlying manifold. The phase transition potential is considered to have a finite set of global minima, where it also vanishes, and a subcritical growth at infinity. Our strategy is to employ the LusternikSchnirelmann and infinitedimensional Morse theories for the vectorial energy functional. To this end, we exploit that the associated ACH energy $\Gamma$converges to the vectorial perimeter for clusters, which combined with some deep theorems from isoperimetric theory yields the suitable set up to apply the photography method. Along the way, the lack of a closed analytic expression for the multiisoperimetric function for clusters imposes a delicate issue. Furthermore, using a transversality theorem, we also show the genericity of the set of metrics for which solutions to our geometric system are nondegenerate.  Past talks 28/07/2020  Olimpio Miyagaki (UFSCAR  São Carlos  Brazil) Title: L^2supercritical and H^{s/2}subcritical and critical fractional NLS equations with partial confinement. Abstract: We study the existence and stability of standing waves for a L^2supercritical and H^{s/2}subcritical and critical NLS equations involving fractional laplacian operator with a partial confinement. This result complements or extends for nonlocal case, the existence result and stability of stand waves obtained in the papers by J. Bellazzini, N. Boussaid, L. Jeanjean and N. Visciglia, Comm. Math. Phys. 253 (2017) and in M. Ohta, Comm. Pure Appl. Anal. 17 (2018), where there were considered the local case with subcritical exponent.  11/08/2020  Edcarlos Domingos da Silva (UFG  Goiânia  Brazil) Title: Quasilinear elliptic problems in the whole R^N. Abstract: In this talk we shall discuss some recent results for quasilinear elliptic problems in the whole R^N. More specially, we consider quasilinear elliptic problems involving the Schrödinger equation. The nonlinear term can be superlinear or asymptotically linear at infinity. Furthermore, we consider also nonlinearities with subcritical or critical growth. The main difficult is to ensure the linking geometry for the associated energy functional taking into account an eigenvalue problem. Another difficulty is to restore the compactness required in variational methods. In order to overcome these difficulties we employ some tools such as Lion's Concentration Compactness Principle together with a fine analysis on the PalaisSmale sequences. Moreover, we also consider quasilinear elliptic systems where the coupling term can be superlinear or asymptotically linear at infinity in a suitable sense. These works are joint with Jefferson S. Silva (UFG), Maxwell L. Lizette (UFG), Marcelo F. Furtado (UnB), José Carlos de Albuquerque (UFPE). link to the seminar recording: https://youtu.be/h1QYjiU4J4  18/08/2020  Jefferson Abrantes dos Santos (UFCG  Campina Grande  Brazil) Title: A limiting free boundary problem for a degenerate operator in OrliczSobolev spaces. Abstract: A free boundary optimization problem involving the phiLaplacian in OrliczSobolev spaces is considered for the case where "phi" does not satisfy the natural conditions introduced by Lieberman. A minimizer u_phi having nondegeneracy at the free boundary is proved to exist and some important consequences are established, namely, the Lipschitz regularity of u_phi along the free boundary, the locally uniform positive density of positivity set of u_phi and that the free boundary is porous with porosity r>0 and has finite (Nr)Hausdorff measure. The method is based on a truncated minimization problem in terms of the Taylor polynomial of "phi" of order 2k. The proof demands to revisit the Lieberman's proof of a Harnack inequality and verify that the associated constant with this inequality is independent of k provided that k is sufficiently large.  25/08/2020  Liliane Maia (UnB  Brasília  Brazil) Title: Nonlinear elliptic systems with local and nonlocal terms. Abstract: We revisit weakly coupled nonlinear Schrödinger systems (NLS) with cubic or higher order power terms of local type and present some recent work on nonexistence, existence and asymptotic behaviour with respect to a parameter of ground state solutions for a class of systems with local and nonlocal nonlinear terms. Particularly, we illustrate with systems of this type which model BoseEinstein condensates and HartreeFockSlater methods in Physics or population dynamics in Biology. This is work in collaboration with Gaetano Siciliano (USP/BR) and Pietro D'Avenia (Politecnico di Bari/IT).  01/09/2020  Pedro Ubilla (USACH  Santiago  Chile) Title: Elliptic systems involving Schrodingeroperators with vanishing potentials. Abstract: Inspired by a wellknown work by BrezisKamin (1992), we prove the existence of a bounded positive solution for some elliptic system involving Schrodinger operators. Furthermore, by imposing additional hypotheses on the nonlinearities we obtain a second solution using variational methods. In this context we consider two particular systems: one gradienttype and the other, Hamiltoniantype. This is a joint work with Denilson Pereira(UFCG) and Juan Arratia(USACH). link to the seminar recording: https://youtu.be/FL98nvxEDbo  08/09/2020  Gaetano Siciliano (USP  São Paulo  Brazil) Title: Existence of solutions for a singular elliptic problem. Abstract: In the talk we show a multiplicity result of positive solutions for a nonlocal elliptic equation which is singular in the nonlinearity. The problem is settled in a bounded domain with Dirichlet boundary conditions. The proof mixes elementary tools in variational methods and topological arguments.  15/09/2020  Leonelo Iturriaga (UTFSM  Santiago  Chile) Title: An existence result for quasilinear equations involving local conditions. Abstract: In this talk we study the existence of weak solutions of a quasilinear equation involving local conditions on the operator, as well as on the nonlinearity, only at zero. The existence result relies considering a parameter and estimates on the gradient of the eventual solutions.  29/09/2020  Pedro Gaspar (UChicago  Chicago  USA) Title: Soluções instáveis de menor energia para uma classe de problemas semilineares em variedades de curvatura positiva com simetrias. Abstract: A caracterização de soluções de menor energia é um problema clássico e ativo em diversos ramos de Equações Diferenciais Parciais e Análise Geométrica. Nesta palestra, discutiremos caracterizações variacionais e geométricas para soluções instáveis de menor energia para certas EDPs semilineares em variedades de curvatura de Ricci nãonegativa com simetrias. Um importante exemplo é a equação de AllenCahn, a qual possui profundas conexões com hipersuperfícies mínimas e de curvatura média constante. Para essa equação, veremos como caracterizar completamente tais soluções em uma esfera. Veremos também como utilizar essa informação para estudar os primeiros valores críticos de uma sequência minmax para a energia associada e um problema de bifurcação. Esse é um trabalho conjunto com Rayssa Caju, Marco A.M. Guaraco e Henrik Matthiesen.  06/10/2020  João Pablo Pinheiro da Silva (UFPA  Belém  Brazil) Title: Existência e Multiplicidade de soluções para um problema de quarta ordem com crescimento crítico Abstract: Neste trabalho vamos estender os resultados clássicos obtimos por por Brézis e Nirenberg em seu trabalho "Positive solutions of nonlinear elliptic equations involving critical Sobolev exponents, Comm. Pure Appl. Math. 36 (1983)" para um operador de quarta ordem, mais especificamente mostramos que se a dimensão N for maior do que 5 e o parâmetro relacionado com a equação está entre zero e o primeiro autovalor do operador BiLaplaciano com condições de Navier, então existe uma solução positiva, se o parâmetro for maior do que ou igual a esse primeiro auto valor, então não existe solução positiva e se o domínio for estrelado e o parâmetro for não positivo então não há solução positiva, mostramos também que quando N=5 e o domínio é uma bola então não há solução positiva quando o parâmetro está perto da origem. No que concerne a multiplicidade usando uma técnica introduzida por Benci e Cerami mostramos que quando o parâmetro é pequeno podemos relacionar o número de soluções positivas da equação com a topologia do domínio.  13/10/2020  Marcos Pimenta (UNESP  Presidente Prudente  Brazil) Title: Anisotropic 1Laplacian problems with unbounded weights Abstract: In this work we prove the existence of nontrivial bounded variation solutions to quasilinear elliptic problems involving a weighted 1Laplacian operator. A key feature of these problems is that weights are unbounded. One of our main tools is the well known CaffarelliKohnNirenberg’s inequality, which is established in the framework of weighted spaces of functions of bounded variation (and that provides us the necessary embeddings between weighted spaces). Additional tools are suitable variants of the Mountain Pass Theorem as well as an extension of the pairing theory by Anzellotti to this new setting.  27/10/2020  Feliciano Vitório (UFAL  Maceió  Brazil) Title: Prescribing the curvature of Riemannian manifolds with boundary Abstract: Let M be a compact connected surface with boundary. We prove that the signal condition given by the GaussBonnet theorem is necessary and sufficient for a given smooth function f on the boundary of M (resp. in M) to be geodesic curvature of the boundary (resp. the Gauss curvature) of some flat metric in M (resp. metric in M with geodesic boundary). In order to provide analogous results for this problem with n>2 we prove some topological restrictions which imply, among other things, that any function that is negative somewhere on the boundary of M (resp. in M) is a mean curvature of a scalar flat metric in M (resp. scalar curvature of a metric in M and minimal boundary with respect to this metric). As an application of our results, we obtain a classification theorem for manifolds with boundary. This is a joint work with Tiarlos Cruz (UFAL).  10/11/2020  Jesse Ratzkin (Universaet der Wuerzburg  Germany) Title: Foliations of an asymptotically flat end by critical capacitors Abstract: I will explain a folitation of an asymptotically flat end of a Riemannian manifold by hypersurfaces which are critical points of a functional arising naturally in potential theory. Each of these hypersurfaces is a perturbation of a large coordinate sphere and admits a solution to an overdetermined boundary value problem. In a key step we must invert the DirichlettoNeumann operator of the Laplacian.  17/11/2020  Erwin Topp Paredes (USACH  Chile) Title: Some results on periodic homogenization for fractional HamiltonJacobi equations Abstract: In this talk we present some results on periodic homogenization for nonlocal HamiltonJacobiBellman equations. We start showing homogenization for evolution problems in two cases: the first one concerns equations where the gradient dominates, and the second concerns the ``critical case", in which there is a competition among the diffusion and the transport term. We conclude the talk with a third result showing a rate of convergence in the case the diffusion dominates. link to the seminar recording: https://youtu.be/WDDRcruyZ2c  08/12/2020  Claudianor Alves (UFCG  Campina Grande  Brazil) Title: Supercritical Neumann problems on unbounded domains Abstract: In this paper, by making use of a new variational principle, we prove existence of nontrivial solutions for two different types of semilinear problems with Neumann boundary conditions in unbounded domains. Namely, we study elliptic equations and Hamiltonian systems on the unbounded domain $\Omega=\R^{m}\times B_r$ where $B_r$ is a ball centered at the origin with radius $r$ in $\mathbb{R}^{n}$. Our proofs consist of several new and novel ideas that can be used in broader contexts. This is a joint work with Abbas Moameni that was accepted for publication in Nonlinearity  16/03/2021  Gabrielle Nornberg (USP  São Carlos  Brazil) Title: Principal spectral curves for LaneEmden fully nonlinear type systems Abstract: In this talk we discuss the phenomenon of two principal spectral curves for LaneEmden systems with fully nonlinear structure. Joint work with Ederson Moreira dos Santos (ICMCUSP), Delia Schiera (La Sapienza Università di Roma), and Hugo Tavares (Técnico de Lisboa)  23/03/2021  Rayssa Caju (UFPB  João Pessoa  Brazil) Title: Existência e comportamento assintótico de soluções singulares de sistemas do tipoYamabe Abstract: Nosso principal objetivo é estudar sistemas de equações de Schrödinger que, do ponto de vista da geometria conforme, são extensões de equações do tipoYamabe fortemente acopladas. Mais especificamente, estudaremos o comportamento assintótico de soluções positivas próximo a uma singularidade isolada e, utilizando as informações obtidas nesse estudo, provaremos existência de soluções singulares utilizando métodos de colagem. Esse tipo de problema exemplifica a rica interação entre a geometria e análise assintótica. Trabalho em colaboração com João Marcos do Ó e Almir Silva Santos.  13/04/2021  Carlos Alberto Santos (UnB  Brasília  Brazil) Title: Multiplicity for a verysingular superlinear quasilinear problem via bifurcation theory Abstract: A pLaplacian elliptic problem in the presence of both strong singular and (p1)superlinear nonlinearities is considered. We employ bifurcation theory, approximation techniques and subsupersolution method to establish the existence of an unbounded branch of positive solutions, which is bounded in positive lambdadirection and bifurcates from infinity at lambda=0. As consequence of the bifurcation result, we determine intervals of existence, nonexistence and, in particular cases, global multiplicity. This is s joint work with Professors Laís Santos  UFV and Jacques Giacomoni  Université de Pau et des Pays de l'Adour.  20/04/2021  Marcos Montenegro (UFMG  Belo Horizonte  Brazil) Title: The effect of diffusions and sources on semilinear elliptic problems Abstract: This talk concerns existence of positive solution and extremal solution as well as dependence with respect to some involved parameters related to certain elliptic problems in the presence of diffusion and source terms.  27/04/2021  Ana Menezes (Princeton University  USA) Title: A twopiece problem for free boundary minimal surfaces in the 3dimensional ball Abstract: In this talk we will prove that every plane passing through the origin divides an embedded compact free boundary minimal surface of the euclidean 3ball in exactly two connected surfaces. This result gives evidence to a conjecture by Fraser and Li. This is a joint work with Vanderson Lima from UFRGS.  04/05/2021  Rafayel Teymurazyan (University of Coimbra  Portugal) Title: Fully nonlinear deadcore systems Abstract: We study fully nonlinear deadcore systems coupled with strong absorption terms. We discover a chain reaction, exploiting properties of an equation along the system. The lack of both the classical Perron's method and comparison principle for the systems requires new tools for tackling the problem. By means of a fixed point argument, we prove existence of solutions, and obtain higher sharp regularity across the free boundary. Additionally, we prove a variant of a weak comparison principle and derive several geometric measure estimates for the free boundary, as well as a Liouville type theorems for entire solutions. These results are new even for linear deadcore systems. This is a joint work with D.J. Araújo  18/05/2021  Almir Santos (UFS  Aracaju  Brazil) Title: Prescribing Curvature of Metrics in Manifolds with Boundary Abstract: In this talk we aim to discuss the problem of prescribe curvature of metrics in manifolds with boundary. We start to talk about the well known Yamabe problem. We are interesting to investigate the influence of the volume and area of the boundary on the scalar and mean curvature. We will show how to use the Yamabe invariant, in the boundary setting, to study a type of KazdanWarnerKobayashi problem in a compact manifold with boundary. This is a joint work with Tiarlos Cruz (UFAL).  25/05/2021  Mateus Sousa (BCAM  Spain) Title: Some sharp inequalities in Fourier restriction theory Abstract: In this talk we will discuss some sharp inequalities in Fourier restriction theory, their connections with partial differential equations, some open problems and also some recent developments. The talk is meant for a broad audience in analysis.  01/06/2021  Lucas Catão Ferreira (UNICAMP  Campinas  Brazil) Title: On nonhomogeneous elliptic problems in the halfspace with nonlinear and singular boundary conditions Abstract: We consider a class of elliptic problems in the halfspace $\mathbb{R}^{n}_+$ with nonhomogeneous boundary conditions containing nonlinearities and critical singular potentials. We obtain existence and regularity results by means of a harmonic analysis approach based on a framework of weighted spaces in Fourier variables. This framework seems to be new in the context of elliptic boundary value problems and allows us to consider Hardy's potential $\lambda_{1} /x^{2}$ in $\mathbb{R}^{n}_+$ and Kato's potential $\lambda_{2}/x^{\prime }$ on the boundary $\partial\mathbb{R}^{n}_+$, as well as their versions with multiple poles, without using the socalled Kato and Hardy inequalities. Singular boundary forcing terms can also be addressed. Moreover, our results cover supercritical nonlinearities, such as $\pm u^p$ in $\mathbb{R}^{n}_+$ and $\pm u^q$ on $\partial\mathbb{R}^{n}_+$ with integers $p>2^{*}1$ and $q>2_{*}1$. Joint work with Nestor F. CastanedaCenturion (UESC, BR)  08/06/2021  Marcelo Furtado (UnB  Brasília  Brazil) Title: Multiplicity of solutions for a nonlinear boundary value problem in the upper halfspace Abstract: We obtain multiple solutions for the nonlinear boundary value problem $$ \Delta u\dfrac{1}{2}\left( x\cdot\nabla u\right) = f(\lambda,x,u), \mbox{ in }\mathbb{R}_{+}^{N}, \qquad \dfrac{\partial u}{\partial\nu}=g(\mu,x',u), \mbox{ on } \partial \mathbb{R}_{+}^{N}, $$ where $\mathbb{R}^N_+$ is the upper halfspace and $\lambda, \mu>0$ are parameters. We consider sublinear, linear and superlinear cases and the function g has critical growth. The talk is based in some works done in collaboration with Karla Sousa (UnB) and João Pablo Silva (UFPA).  22/06/2021  Maria Andrade (UFS  Brazil) Title: Resultados de classificação para superfícies CMC de bordo livre Abstract: Em 1995, A. Ros e E. Vergasta provaram que uma superfície Sigma compacta, orientável, estável com bordo livre na bola fechada B do R3 deve ser um equador planar, uma calota esférica ou uma superfície de gênero 1 com no máximo duas componentes no bordo. I. Nunes, usando um balanceamento modificado do tipo Hersch, provou que Sigma não pode ter gênero 1. Podemos citar ainda trabalhos de classificação via existência de uma função convexa como por exemplo o de L. Ambrozio e I. Nunes no caso de superfície mínima em B ou ainda, E. Barbosa, M. Cavalcante e E. Pereira no caso de superfície CMC em B. Consideramos M=({B}^3_r,\bar{g}) como a bola Euclidiana de dimensão 3 com raio r, equipada com uma métrica \bar{g}=e^{2h}< , > conforme à métrica Euclidiana, onde a função h=h(x) depende somente da distância de x ao centro da bola {B}^3_r. Mostramos que se uma superfície CMC Sigma em M satisfaz uma condição de pinching do comprimento do tensor da segunda forma sem traço, o qual envolve a função de suporte de Sigma, o campo vetorial conforme e sua função potencial, então Sigma é um disco ou um anel rotacionalmente simétrico. Este é um trabalho em parceria com Ezequiel Barbosa (UFMG) e Edno Pereira (UFMG).  29/06/2021  Diego Marcon (UFRGS  Brazil) Title: A general obstacle problem in American option pricing: regularity of solutions Abstract: In this talk, we consider a general parabolic obstacle problem that naturally arises in American options pricing. We introduce obstacle problems in somewhat elementary words and then proceed to present our model in some detail. The parabolic operator that shows up is a combination of nonlocal diffusion terms and a drift term. We prove optimal regularity of solutions in space and almost optimal regularity in time. This is a joint work with Henrique Borrin (UNICAMP). link to the seminar recording: https://youtu.be/cuY3nffPuHI  06/07/2021  Levi Lopes de Lima (UFC  Brazil) Title: Operadores elípticos em variedades cônicas: exemplos e aplicações Abstract: Revisaremos a teoria de operadores elípticos em variedades com singularidades cônicas isoladas (como desenvolvida por Schulze, Lesch, Schrohe, entre outros), com ênfase naqueles operadores que frequentemente aparecem em aplicações geométricas (Laplaciano, Dirac, etc.) Em seguida, discutiremos algumas aplicações deste formalismo, incluindo um resultado de prescrição da curvatura escalar em tais variedades (baseado em arXiv:2104.13882) link to the seminar recording: https://youtu.be/b3ggndFsENY  20/07/2021  Hugo Tavares (Inst. Superior Técnico  Portugal) Title: Free boundary problems with longrange interaction Abstract: In this talk we consider a class of variational shape optimisation problems for densities that repel each other at a certain distance. Typical examples are given by the Dirichlet functional and the Rayleigh functional minimised in the class of functions that attain some H^1 boundary conditions, subject to the constraint that the supports of different densities are at a certain fixed distance. We show a connection with solutions to variational elliptic systems with nonlocal competing interactions, investigate the optimal regularity of the solutions (and prove uniform estimates with respect to the distance parameter), prove a freeboundary condition and derive some preliminary results characterising the free boundary. The talk is based in the following works: [1] N. Soave, H. Tavares, S. Terracini, A. Zilio, Variational problems with longrange interaction, Arch. Rational Mech. Anal.228(2018), 743–772. [2]Nicola Soave, Hugo Tavares and Alessandro Zilio, Free boundary problems with longrange interactions: uniform Lipschitz estimates in the radius, arXiv:2106.03661. link to the seminar recording: https://youtu.be/6MZyEtVyxuY  27/07/2021  David Costa (University of Nevada Las Vegas  EUA) Title: Multiple Solutions for Heterogeneous Semilinear Equations in Exterior Domains of R^2 Abstract: We prove some multiplicity results, in the BeppoLevi space, for solutions of a class of semilinear boundary value problems defined in exterior domains of the twodimensional Euclidean space. We deal with the existence of extremal constantsign solutions and nodal solutions for this problem. The main tools in the arguments developed in this paper are the Kelvin transform, the duality method, the BrezisNirenberg theorem, and related variational tools. link to the seminar recording: https://youtu.be/1oZqd0YBkNI  17/08/2021  Ederson Santos (USPSão Carlos  Brazil) Title: Unique continuation principles for systems Abstract: In this talk I will discuss on some recent unique continuation results for systems of elliptic partial differential equations satisfying a suitable superlinearity condition. As an application, we obtain nonexistence of nontrivial (not necessarily positive) radial solutions, in the critical and supercritical regimes, for the LaneEmden posed in a ball. Some of our results also apply to general fully nonlinear operators, such as Pucci's extremal operators, being new even for scalar equations. This is a joint work with Gabrielle Nornberg and Nicola Soave.  17/08/2021  Boyan Sirakov (PUC  Rio  Brazil) Title: Regularidade global para soluções fracas de EDPs elípticas degeneradas. Abstract: Vamos apresentar um panorama geral da teoria da regularidade global para soluções fracas de viscosidade de EDP elípticas, tanto uniformemente elípticas quanto com elipticidade degenerada, desenvolvida durante as últimas décadas. Vamos detalhar alguns resultados recentes para equações degeneradas na forma não divergente. link to the seminar recording: https://youtu.be/IeR4jv2q0ic  24/08/2021  Mónica Clapp (Universidad Nacional Autónoma de México) Title: Optimal partitions for the Yamabe equation Abstract: The Yamabe equation on a Riemannian manifold (M,g) is of relevance in differential geometry. A positive solution to it gives rise to a metric on M which has constant scalar curvature and is conformally equivalent to the given metric g. An optimal lpartition for the Yamabe equation is a cover of M by l pairwise disjoint open subsets such that the Yamabe equation with Dirichlet boundary condition has a least energy solution on each one of these sets, and the sum of the energies of these solutions is minimal. We will present some recent results obtained in collaboration with Angela Pistoia (La Sapienza Università di Roma) and Hugo Tavares (Universidade de Lisboa) that establish the existence and qualitative properties of such partitions. We will also present some results on symmetric optimal partitions obtained in collaboration with Angela Pistoia, and with Alberto Saldaña (UNAM) and Andrzej Szulkin (Stockholm University).  31/08/2021  João Henrique Andrade (USP  São Paulo  Brazil) Title: Compactness within the space of complete, constant Qcurvature metrics on the sphere with isolated singularities Abstract: This talk addresses the moduli space of complete, conformally flat metrics metrics on a sphere with k punctures having constant positive Qcurvature and positive scalar curvature. Previous work has shown that such metrics admit an asymptotic expansion near each puncture, allowing one to define an asymptotic necksize of each singular point. We prove that any set in the moduli space such that the distances between distinct punctures and the asymptotic necksizes all remain bounded away from zero is sequentially compact, mirroring a theorem of D. Pollack about singular Yamabe metrics. Along the way, we define a radial Pohozaev invariant at each puncture and refine some a priori bounds of the conformal factor, which may be of independent interest.  14/09/2021  Evelina Shamarova (UFPB  João Pessoa  Brazil) Title: Singular solutions to kHessian equations with fastgrowing nonlinearities Abstract: In this talk, we deal with a Dirichlet problem for a kHessian equation with a quite general fastgrowing nonlinearity on a unit ball. We prove the existence of a radial singular solution and obtain its exact asymptotic behavior in a neighborhood of the origin. We furthermore demonstrate that this specific singular solution allows to study properties of radial regular solutions such as bifurcation diagrams and multiplicity, where an important tool is the number of intersection points between the singular and regular solutions for rescaled problems. In the particular case of the exponential nonlinearity, we obtain the convergence of regular solutions to the singular. This talk is based on a joint work with João Marcos do Ó and Esteban da Silva. link to the seminar recording: https://youtu.be/mG_6phpicA  28/09/2021  Ederson Braga (UFC  Fortaleza  Brazil) Title: Sobre o Teorema de Regularidade de Fronteira de Krylov Abstract: Nesta palestra apresentamos alguns avanços sobre o Teorema de Regularidade 𝐶1,𝛼 de fronteira devido a N. Krylov originalmente provado na década de 80. Os últimos avanços que tenho conhecimento datam de 2020. A fim de apresentar resultados, demonstrações e técnicas usadas neste tipo de resultado, tomamos um caso particular coberto pelo Teorema de Krylov para expôlo de modo formal. This webinar was recorded and will be available soon  05/10/2021  Ezequiel Barbosa (UFMG  Belo Horizonte  Brazil) Title: On noncompact free boundary minimal hypersurfaces in the Riemannian Schwarzschild Spaces Abstract: In this talk we will discuss on the existence and the Morse index of an unbounded free boundary minimal hypersurface of the Riemannnian Schwarzschild This webinar was recorded and will be available soon  12/10/2021  Stefano Nardulli (UFABC  São Paulo  Brazil) Title: On noncompact free boundary minimal hypersurfaces in the Riemannian Schwarzschild Spaces Abstract: In this paper we want to give a result on the existence and the number of solutions of the Van der WaalsCahnHilliard two phase transition equation with a small volume constraint inside a compact Riemannian manifold M^n without boundary. We assume that the double well potential is regular enough and satisfies suitable growth conditions at infinity to apply the abstract topological method of photography for small temperatures close to the 0º Kelvin and small enclosed volume. Finally we send the temperature parameter to zero for a fixed small enclosed volume to find a lower bound on the number of solutions that depends just on topological invariants of the manifold M. This is a joint work with Vieri Benci (Univ. Pisa), Luis Eduardo Osorio Acevedo (IMEUSP), Paolo Piccione (IMEUSP). This webinar was recorded and will be available soon  19/10/2021  Tiarlos Cruz (UFAL  Alagoas  Brazil) Title: Deformations and prescriptions of scalar curvature and mean curvature Abstract: I will talk about a map involving the scalar curvature and mean curvature on the space of Riemannian metrics of a compact manifold with non empty boundary. We will include some prescribing curvature results. Moreover, I will discuss this map under the effect of the volume and the area of the boundary through two approaches: on the one hand, we vary the volume or area of the boundary and, on the other hand, we restrict it to metrics of unit volume or unit area of the boundary. This talk is based on joint works with Almir Santos (UFS) and Feliciano Vitório (UFAL). This webinar was recorded and will be available soon  09/11/2021  Anna Maria Candela (Università degli Studi di Bari  ITA) Title: A quasilinear modified Schrodinger equation: from bounded domains to the Euclidean space This webinar was recorded and will be available soon  23/11/2021  José Nazareno Gomes (UFSCAR São Carlos  Brazil) Title: Eigenvalue estimates of the drifted ChengYau operator on bounded domains in pinched CartanHadamard manifolds Abstract: In this talk, we will see how a Bochner type formula can be used to establish universal inequalities for the eigenvalues of the drifted ChengYau operator on a bounded domain in a pinched CartanHadamard manifold with the Dirichlet boundary condition. In the first theorem, the hyperbolic space case is treated in an independent way. For the more general setting, we first establish a Rauch comparison theorem for the ChengYau operator and two estimates associated with the Bochner type formula for this operator. Next, we get some integral estimates of independent interest. As an application, we compute our universal inequalities. In particular, we obtain the corresponding inequalities for both ChengYau operator and drifted Laplacian cases, and we recover the known inequalities for the Laplacian case. We also obtain a rigidity result for a ChengYau operator on a class of bounded annular domains in a pinched CartanHadamard manifold. In particular, we can use, e.g., the potential function of the Gaussian shrinking soliton to obtain such a rigidity for the Euclidean space case. This is a joint work with professor Júlio C. M. da Fonseca of the Centro de Estudos Superiores de Parintins, Universidade do Estado do Amazonas, Parintins, Amazonas, Brazil.  30/11/2021  Pierluigi Benevieri (USP São Paulo  Brazil) Title: Periodic positive solutions for delay equations and the use of the topological degree Abstract: We present a brief summary of the literature concerning periodic positive solutions for differential equations and, then, a joint work with with Pablo Amster (Universidad de Buenos Aires, Argentina) and Julián Haddad (Universidade Federal de Minas Gerais, Brazil), which deals with an extension to delay problems of some recent results by G. Feltrin and F. Zanolin. They obtained existence and multiplicity results for positive periodic solutions to nonlinear e nondelayed differential equations of second order with periodic or Newmann boundary conditions and special assumptions on nonlinear part of the equations. We studied analogous problems with dependence of a constant delay. Our approach, as well as that of Feltrin and Zanolin, is topological and based on the coincidence degree introduced by J. Mawhin. This webinar was recorded and will be available soon  08/03/2022  Kanishka Perera (Florida Institute of Technology  USA) Title: New multiplicity results for critical pLaplacian problems Abstract: We prove new multiplicity results for the BrezisNirenberg problem for the pLaplacian. Our proofs are based on a new abstract critical point theorem involving the Z_2cohomological index that requires less compactness than the (PS) condition. This webinar was recorded and will be available soon  22/03/2022  Igor Verbitsky (University of Missouri System  USA) Title: Some classes of solutions of quasilinear elliptic equations of the pLaplace type Abstract: We consider positive solutions to quasilinear elliptic equations of the pLaplace type with subnatural growth terms, and coefficients and data which are nonnegative measurable functions (or locally finite Radon measures). General solutions, as well as certain classes of solutions, including BMO solutions, will be treated. We will discuss bilateral pointwise estimates of solutions, along with sharp criteria for their existence, based on nonlinear potential theory. Our results hold for more general quasilinear operators, as well as for the fractional Laplace operators.  29/03/2022  Otared Kavian (Université Paris–Saclay (site de Versailles)  France) Title: Remarks on the existence of equilibrium in some parabolic evolution equations Abstract: We consider a few examples of parabolic evolution equations in the whole space, linear or nonlinear, for which one can show the existence of a positive equilibrium and then one may prove convergence of positive solutions to a multiple of the equilibrium. We consider a (weekly) nonlinear mutation selection model, known as replicatormutator equation in evolutionary biology. These models involve a nonlocal mutation kernel and a confining fitness potential. We prove that the long time behaviour of the Cauchy problem is determined by the underlying principal eigenelement of the underlying linear operator. To do so, through a minimization problem under constraints, we prove first the existence of such an eigenlement. Then we first analyze the linear evolution problem through the proof of the existence of a spectral gap, by taking advantage of the theory of strongly continuous semigroups of positive operators. We conclude with the analysis of the nonlinear problem.  12/04/2022  Leonardo Francisco Cavenaghi (University of Fribourg  Switzerland) Title: Old and new connections between elliptic PDE's and symmetries Abstract: It is classical nowadays that the solution to the Yamabe problem took a difficult path due to the lack of compact embeddings of Sobolev spaces for critical exponents. Not that well known, however, are the results firstly appearing in the now classical work of E. Hebey and M. Vaugon, where the presence of symmetries on Riemannian manifolds make it way easier to deal with not only the Yamabe problem, but other critical elliptic PDE's via standard variational methods. In this talk we explore this old feature to show how to completely solve the KazdanWarner under the presence of symmetries induced both by group actions and by singular Riemannian foliations (SRF). These results were obtained in collaboration to Prof. João Marcos do Ó and Prof. Llohann Sperança, in the group action case, and to Prof. Marcos Alexandrino in the SRF setting. Instead of focusing on the geometric consequences of these results, we shall mostly emphasize how the same setup can be applied to other problems, such as in the study of optimal constants on Sobolev embeddings, assuming symmetries hypothesis. We also intend to provide a glance about the plausibility of some old conjectures under these symmetric assumptions.  26/04/2022  Jianjun Zhang (Chongqing Jiaotong University  China) Title: Another look at planar SchrodingerNewton systems Abstract: In this talk, we focus on the existence of positive solutions to a planar SchrodingerNewton system with subcritical or critical growth. A new variational approach is established and enables us to study such problem in the Sobolev space as usual. The analysis developed in this paper also allows to investigate the relation between a SchrodingerNewton system of Riesztype and a SchrodingerPoisson system of logarithmictype. Furthermore, this new approach can provide a new look at the planar SchrodingerNewton system and may have some potential applications in various related problems. This is a joint work with Zhisu Liu, Vicent iu D. Radulescu and Chunlei Tang and one with Zhisu Liu, Vicent iu D. Radulescu.  10/05/2022  Kaye Silva (UFG  Brazil) Title: The fibering method applied to the level sets of a family of functionals Abstract: Given an oneparameter family of $C^1$functionals, $\Phi_\mu:X\to \mathbb{R}$, defined on an uniformly convex Banach space $X$, we describe a method that permit us find critical points of $\Phi_\mu$ at some energy level $c\in \mathbb{R}$. In fact, we show the existence of a sequence $\mu(n,c)$, $n\in \mathbb{N}$, such that $\Phi_{\mu(n,c)}$ has a critical level at $c\in \mathbb{R}$, for all $n\in \mathbb{N}$. Moreover, we show some good properties of the curves $\mu(n,c)$, with respect to $c$ (for example, they are Lipschitz), and as a consequence of this analysis, we recover many know results on the literature concerning bifurcations of elliptic partial differential equations. Furthermore we prove new results for a large class of elliptic partial differential equations, which includes, for example, Ouyang, LaneEnden, ConcaveConvex, Kirchhoff and SchrodingerBoppPodolsky type equations. 

Webinar via Google Meet. Each webinar has its own link.  
Anyone is invited to attend the meetings.


João Marcos do Ó (coordinator  organizer): jmbo@academico.ufpb.br Bruno Ribeiro (organizer): bhcr@academico.ufpb.br


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