Article
Mathematics, Applied
Akos Nagy
Summary: We study stationary solutions to the Keller-Segel equation on curved planes and prove the necessity of mass being 8 pi with a sharp decay bound. We establish a correspondence between stationary solutions and positively curved Riemannian metrics on the sphere and show the nonexistence of solutions in certain situations. Additionally, we prove a curved version of the logarithmic Hardy-Littlewood-Sobolev inequality and demonstrate that the Keller-Segel free energy is bounded from below when the mass is 8 pi, even in the curved case.
PROCEEDINGS OF THE ROYAL SOCIETY OF EDINBURGH SECTION A-MATHEMATICS
(2023)
Article
Mathematics, Applied
Vincent Calvez, Jose Antonio Carrillo, Franca Hoffmann
Summary: In this study, a generalized Keller-Segel model with non-linear porous medium type diffusion and non-local attractive power law interaction is considered, with a focus on potentials more singular than Newtonian interaction. Uniqueness of stationary states in different regimes is shown, with the key result being a sharp functional inequality in the radial setting.
NONLINEAR ANALYSIS-THEORY METHODS & APPLICATIONS
(2021)
Article
Mathematics
Michael Winkler
Summary: This study examines the solution behavior of a fully parabolic cross-diffusion system under specific boundary conditions, introducing the concept of singularity limit and deriving new conclusions.
JOURNAL OF DIFFERENTIAL EQUATIONS
(2022)
Article
Mathematics
Jaewook Ahn, Kyungkeun Kang, Jihoon Lee
Summary: The passage discusses a class of logarithmic Keller-Segel type systems modeling the spatio-temporal behavior of chemotactic cells or criminal activities in spatial dimensions two and higher. It establishes the existence of classical solutions globally in time under certain assumptions on parameter values and given functions. The text also introduces a new type of small initial data to obtain global classical solutions and discusses the long-time asymptotic behaviors of solutions.
JOURNAL OF DIFFERENTIAL EQUATIONS
(2021)
Article
Biochemical Research Methods
Leon Avery, Brian Ingalls, Catherine Dumur, Alexander Artyukhin
Summary: Collective behaviors in Starved first-stage larvae of the nematode Caenorhabditis elegans are known to produce large-scale organization. A mathematical model was developed to explain how and why the larvae aggregate, focusing on chemotaxis and the role of two chemical signals. Knocking out the sensory receptor gene srh-2 resulted in irregularly shaped aggregates, suggesting that mutant worms moved slower than wild type.
PLOS COMPUTATIONAL BIOLOGY
(2021)
Article
Mathematics
Jose A. Carrillo, Jingyu Li, Zhi-An Wang
Summary: This study investigates the existence and stability of boundary spike-layer solutions of the Keller-Segel system with logarithmic singular sensitivity in the half space, and introduces a novel strategy to handle the singularity through a transformation and suitable weighted energy estimates. The boundary spike-layer steady state is shown to be asymptotically nonlinearly stable under appropriate perturbations, marking a significant advancement in understanding the dissipative structure of the system.
PROCEEDINGS OF THE LONDON MATHEMATICAL SOCIETY
(2021)
Article
Mathematics, Applied
Michael Winkler
Summary: By utilizing a novel approach, this study analyzes a quasilinear Keller-Segel system with density-dependent migration rates, and derives a result on global existence and boundedness under an optimal condition on the strength of cross-diffusion relative to diffusion.
APPLIED MATHEMATICS LETTERS
(2021)
Article
Mathematics, Applied
Ujjal Das
Summary: The text discusses weighted logarithmic Sobolev inequalities and logarithmic Hardy inequalities in various spaces and conditions, exploring their properties and related theorems.
JOURNAL OF MATHEMATICAL ANALYSIS AND APPLICATIONS
(2021)
Article
Mathematics, Applied
Mario Bezerra, Claudio Cuevas, Clessius Silva, Herme Soto
Summary: This work investigates the time-fractional doubly parabolic Keller-Segel system in Double-struck capital R-N (N >= 1) and establishes refined results on the large time behavior of solutions. The study involves the well-posedness and asymptotic stability of solutions in Marcinkiewicz spaces, achieved through appropriate estimation of system nonlinearities and analysis based on Duhamel-type representation formulae and the Kato-Fujita framework with a fixed-point argument using a suitable time-dependent space.
SCIENCE CHINA-MATHEMATICS
(2022)
Article
Mathematics
Piotr Biler, Alexandre Boritchev, Lorenzo Brandolese
Summary: This paper studies the global existence of the parabolic-parabolic Keller-Segel system in R-d, d >= 2. It is proven that global solutions are obtained for initial data of arbitrary size as long as the diffusion parameter tau is large enough in the equation for the chemoattractant. The analysis improves earlier results and extends them to any dimension d >= 3. Optimal size conditions for the global existence of solutions are discussed, and two toy models are introduced to illustrate the fact, showing finite time blowup for a class of large solutions in a companion paper.
JOURNAL OF DIFFERENTIAL EQUATIONS
(2023)
Article
Mathematics, Applied
Santanu Saha Ray
Summary: In this paper, the similarity method is employed to solve a fractional Keller-Segel model with a nonlocal fractional Laplace operator, and the results are verified through comparison of the fractional centred difference method and the weighted shifted Gruwald-Letnikov difference method, demonstrating the accuracy and efficiency of the proposed numerical schemes.
MATHEMATICAL METHODS IN THE APPLIED SCIENCES
(2021)
Article
Mathematics
Wenbin Lyu
Summary: This paper deals with a class of signal-dependent motility Keller-Segel systems, investigates the existence of global-in-time solutions in a bounded domain, and rules out blow-up phenomenon by superlinear damping.
JOURNAL OF DIFFERENTIAL EQUATIONS
(2022)
Article
Mathematics
Xiangsheng Xu
Summary: This paper investigates the initial boundary value problem for the Keller-Segel model with nonlinear diffusion. The study shows that nonlinear diffusion can prevent overcrowding and proves that solutions are bounded under certain conditions, expanding the existing knowledge in this area. The results also suggest that the Keller-Segel model can have bounded solutions and blow-up solutions simultaneously.
JOURNAL OF DIFFERENTIAL EQUATIONS
(2021)
Article
Mathematics, Applied
Mario Fuest, Johannes Lankeit, Yuya Tanaka
Summary: In this paper, we study quasilinear Keller-Segel systems with indirect signal production and prove the existence and boundedness of the solution under certain conditions. We also show that the solution blows up in finite or infinite time under certain conditions.
MATHEMATICAL METHODS IN THE APPLIED SCIENCES
(2023)
Article
Mathematics
Yuki Naito
Summary: The study focuses on the simplest parabolic-elliptic model of chemotaxis in space dimensions N >= 3, and identifies optimal conditions on the initial data for finite time blow-up and global existence of solutions based on stationary solutions. The argument is based on the analysis of the Cauchy problem for the transformed equation involving the averaged mass of the solution.
JOURNAL OF DIFFERENTIAL EQUATIONS
(2021)
Article
Physics, Mathematical
Denis Bonheure, Jean Dolbeault, Maria J. Esteban, Ari Laptev, Michael Loss
COMMUNICATIONS IN MATHEMATICAL PHYSICS
(2020)
Article
Mathematics
Jean Dolbeault, Xingyu Li
Summary: This paper focuses on logarithmic Hardy-Littlewood-Sobolev inequalities in the 2D Euclidean space with an external potential exhibiting logarithmic growth. The introduction of a new parameter through the coupling with the potential leads to two different regimes. The attractive regime reflects the standard logarithmic Hardy-Littlewood-Sobolev inequality, while the second regime results in a reverse inequality, enabling the bounding of the free energy of a drift-diffusion-Poisson system from below.
INTERNATIONAL MATHEMATICS RESEARCH NOTICES
(2021)
Article
Mathematics, Applied
Jean Dolbeault, Maria J. Esteban
ADVANCED NONLINEAR STUDIES
(2020)
Article
Physics, Mathematical
Lanoir Addala, Jean Dolbeault, Xingyu Li, M. Lazhar Tayeb
Summary: This paper focuses on the linearized Vlasov-Poisson-Fokker-Planck system in the presence of an external potential of confinement. Through hypocoercivity methods and a specific notion of scalar product adapted to the Poisson coupling, the large time behavior of the solutions is investigated with uniform estimates in the diffusion limit. As an application in a simple case, the one-dimensional case is studied and exponential convergence of the nonlinear Vlasov-Poisson-Fokker-Planck system is proven without any small mass assumption.
JOURNAL OF STATISTICAL PHYSICS
(2021)
Article
Mathematics, Applied
Kleber Carrapatoso, Jean Dolbeault, Frederic Herau, Stephane Mischler, Clement Mouhot
Summary: We prove functional inequalities on vector fields u : R-d -> R-d when R-d is equipped with a bounded measure e(-phi) dx that satisfies a Poincare inequality, and study associated self-adjoint operators. The weighted Korn inequality compares the differential matrix Du, once projected orthogonally to certain finite-dimensional spaces, with its symmetric part D(s)u and, in an improved form of the inequality, an additional term del phi.u. We also consider Poincare-Korn inequalities for estimating a projection of u by D(s)u and zeroth-order versions of these inequalities obtained using the Witten-Laplace operator. The constants depend on geometric properties of the potential phi and the estimates are quantitative and constructive. These inequalities are motivated by kinetic theory and related with the Korn inequality (1906) in mechanics, which compares Du and D(s)u on a bounded domain.
ARCHIVE FOR RATIONAL MECHANICS AND ANALYSIS
(2022)
Article
Physics, Mathematical
Emeric Bouin, Jean Dolbeault, Laurent Lafleche
Summary: This paper investigates the large time behavior of kinetic equations without confinement, focusing on collision operators with fat tailed local equilibria and their anomalous diffusion limit. The study develops an L-2-hypocoercivity approach at the kinetic level to establish a decay rate compatible with the fractional diffusion limit.
COMMUNICATIONS IN MATHEMATICAL PHYSICS
(2022)
Article
Mathematics, Applied
Jean Dolbeault
Summary: Interpolation inequalities play a crucial role in analysis, mathematical physics, nonlinear PDEs, and other areas of Science. Research interests have shifted towards qualitative questions and the use of entropy methods, which provide insights into optimal rates of decay and stability in various inequalities. The framework of entropy methods allows for the study of nonlinear regimes and their linearized counterparts, leading to optimality results and symmetry properties.
MILAN JOURNAL OF MATHEMATICS
(2021)
Article
Mathematics, Applied
Jean Dolbeault, An Zhang
Summary: The carre du champ method is a powerful technique for proving interpolation inequalities with explicit constants in presence of a non-trivial metric on a manifold. The method applies to some classical Gagliardo-Nirenberg-Sobolev inequalities on the sphere, with optimal constants. Very nonlinear regimes close to the critical Sobolev exponent can be covered using nonlinear parabolic flows of porous medium or fast diffusion type.
DISCRETE AND CONTINUOUS DYNAMICAL SYSTEMS
(2022)
Correction
Mathematics
Jean Dolbeault, Maria J. Esteban, Eric Sere
Summary: This corrigendum addresses some overlooked closability issues in [1].
JOURNAL OF FUNCTIONAL ANALYSIS
(2023)
Article
Mathematics
Jean Dolbeault, Rupert L. Frank, Louis Jeanjean
Summary: In two dimensions, we study the free energy and ground state energy of the Schrodinger-Poisson system coupled with a logarithmic nonlinearity, taking into account scaling invariances, external potential with minimal growth, and new logarithmic interpolation inequalities. This two-dimensional model serves as a limit case of more classical problems in higher dimensions, and considers both repulsive and attractive forces.
COMPTES RENDUS MATHEMATIQUE
(2021)
Review
Physics, Mathematical
Denis Bonheure, Jean Dolbeault, Maria J. Esteban, Ari Laptev, Michael Loss
Summary: This paper explores nonlinear interpolation inequalities associated with Schrodinger operators involving Aharonov-Bohm magnetic potentials, focusing on symmetry and considering various cases in different geometric settings. The emphasis is on new results and methods, particularly in the presence of a magnetic field, with the most significant applications being new magnetic Hardy inequalities in dimensions 2 and 3.
REVIEWS IN MATHEMATICAL PHYSICS
(2021)
Article
Mathematics
E. Bouin, J. Dolbeault, L. Lafleche, C. Schmeiser
Summary: Hypocoercivity methods are used in linear kinetic equations with sub-exponential decay of local equilibria, deriving global rates of decay through Nash type estimates. The method is applicable to Fokker-Planck and scattering collision operators, utilizing weighted Poincare inequality and norms with various weights. Weighted Poincare inequalities are advantageous in describing convergence rates to local equilibrium without the need for extra regularity assumptions, covering transitions from super-exponential and exponential to sub-exponential local equilibria.
MONATSHEFTE FUR MATHEMATIK
(2021)
Article
Mathematical & Computational Biology
Jean Dolbeault, Gabriel Turinici
MATHEMATICAL MODELLING OF NATURAL PHENOMENA
(2020)
Article
Mathematics, Applied
Emeric Bouin, Jean Dolbeault, Christian Schmeiser
KINETIC AND RELATED MODELS
(2020)
Article
Mathematics, Applied
Jean Dolbeault, Marta Garcia-Huidobro, Raul Manasevich
DISCRETE AND CONTINUOUS DYNAMICAL SYSTEMS
(2020)