This article considers the following higher-dimensional quasilinear parabolic-parabolic-ODE chemotaxis system with generalized Logistic source and homogeneous Neumann boundary conditions{ut=∇⋅(D(u)∇u)−∇⋅(S(u)∇v)+f(u),...This article considers the following higher-dimensional quasilinear parabolic-parabolic-ODE chemotaxis system with generalized Logistic source and homogeneous Neumann boundary conditions{ut=∇⋅(D(u)∇u)−∇⋅(S(u)∇v)+f(u),x∈Ω,t>0 vt=Δv+w−v,x∈Ω,t>0,wt=u−w,x∈Ω,t>0,in a bounded domainΩ⊂R^n(n≥2)with smooth boundary ∂Ω,where the diffusion coefficient D(u)and the chemotactic sensitivity function S(u)are supposed to satisfy D(u)≥M1(u+1)^−αand S(u)≤M2(u+1)^β,respectively,where M1,M2>0 and α,β∈R.Moreover,the logistic source f(u)is supposed to satisfy f(u)≤a−μu^γ with μ>0,γ≥1,and a≥0.Asα+2β<γ−1+2γ/n,we show that the solution of the above chemotaxis system with sufficiently smooth nonnegative initial data is uniformly bounded.展开更多
In this paper, we use contraction mapping principle, operator-theoretic approach and some uniform estimates to establish local solvability of the parabolic-hyperbolic type chemotaxis system with fixed boundary in 1-di...In this paper, we use contraction mapping principle, operator-theoretic approach and some uniform estimates to establish local solvability of the parabolic-hyperbolic type chemotaxis system with fixed boundary in 1-dimensional domain. In addition, local solvability of the free boundary problem is considered by straightening the free boundary.展开更多
This work explores the predator-prey chemotaxis system with two chemicals {u_(t) = Δu + ∇ ・ (u∇v) + μ_(1)u(1 − u − α_(1)w), x ∈ Ω, t > 0,v_(t )= Δv −α_(1)v + β_(1)w, x ∈ Ω, t > 0,w_(t) = Δw − ξ∇ ・ (w...This work explores the predator-prey chemotaxis system with two chemicals {u_(t) = Δu + ∇ ・ (u∇v) + μ_(1)u(1 − u − α_(1)w), x ∈ Ω, t > 0,v_(t )= Δv −α_(1)v + β_(1)w, x ∈ Ω, t > 0,w_(t) = Δw − ξ∇ ・ (w∇z) + μ_(2)w(1 + α_(2)u − w), x ∈ Ω, t > 0,z_(t) =Δz −α_(2)z +β_(2)u, x ∈ Ω, t > 0, in an arbitrary smooth bounded domainΩ■R^(n) under homogeneous Neumann boundary conditions.The parameters in the system are positive.We first prove that if n≤3,the corresponding initial-boundary value problem admits a unique global bounded classical solution,under the assumption thatχ,ξ,μ_(i),a_(i),α_(i) andβ_(i)(i=1,2)satisfy some suitable conditions.Subsequently,we also analyse the asymptotic behavior of solutions to the above system and show that·when a_(1)<1 and bothμ1/χ^(2) andμ2/ξ^(2) are sufficiently large,the global solution(u,v,w,z)of this system exponentially converges to(1-a_(1)/1+a_(1)a_(2),β_(1)(1+a_(2))/α_(1)(1+a_(1)a_(2)),1+a_(2)/1+a_(1)a_(2),β_(2)(1-a_(1))/α_(2)(1+a_(1)a_(2)))as t→∞;·when a1>1 andμ_(2)/ξ_(2) is sufficiently large,the global bounded classical solution(u,v,w,z)of this system exponentially converges to(0,α_(1)/β_(1),1,0)as t→∞;·when a1=1 andμ_(2)/ξ_(2) is sufficiently large,the global bounded classical solution(u,v,w,z)of this system polynomially converges to(0,α_(1)/β_(1),1,0)as t→∞.展开更多
This paper is devoted to dealing with the parabolic-elliptic-elliptic attraction-repulsion chemotaxis system.We aim to understand the competition among the repulsion,the attraction,the nonlinear productions and give c...This paper is devoted to dealing with the parabolic-elliptic-elliptic attraction-repulsion chemotaxis system.We aim to understand the competition among the repulsion,the attraction,the nonlinear productions and give conditions of global existence and blow-up for the two-dimensional attraction-repulsion chemotaxis system。展开更多
In Hashim and Harfash(Appl.Math.Comput.2021),using a finite element method,the attraction-repulsion chemotaxis model(P)in space is discretised;finite differences were used to do the same in time.Furthermore,the existe...In Hashim and Harfash(Appl.Math.Comput.2021),using a finite element method,the attraction-repulsion chemotaxis model(P)in space is discretised;finite differences were used to do the same in time.Furthermore,the existence of a global weak solution to the system(PΔt M)was demonstrated by means of analysis of the convergence of the fully discrete approximate problem(P h,Δt M,).Moreover,the functions{U,Z,V}were proved to represent a global weak solution to the system(PΔt M)by means of a passage to the limit,h→0 of the approximate system.This paper’s purpose is to demonstrate that the solutions can be bounded,independent of M.The analysis contained in this paper illustrates the idea of the existence of weak solutions to the model(P),that requires passing to the limits,Δt→0+and M→∞.The time stepΔt is subsequently linked to the cutoff parameter M>1 by positing a demand thatΔt=o(M−1),as M→∞,with the result that the cutoff parameter becomes the only parameter in the problem(PΔt M).The solutions can be bounded,independ-ent of M,with the use of special energy estimates,as demonstrated herein.Then,these M-independent bounds on the relative entropy are employed with the purpose of deriving M-independent bounds on the time-derivatives.Additionally,compactness arguments were utilised to explore the convergence of the finite element approximate problem.The conclu-sion was that a weak solution for(P)existed.Finally,we introduced the error estimate and the implicit scheme was used to perform simulations in one and two space dimensions.展开更多
In this paper,a finite element scheme for the attraction-repulsion chemotaxis model is analyzed.We introduce a regularized problem of the truncated system.Then we obtain some a priori estimates of the regularized func...In this paper,a finite element scheme for the attraction-repulsion chemotaxis model is analyzed.We introduce a regularized problem of the truncated system.Then we obtain some a priori estimates of the regularized functions,independent of the regularization parameter,via deriving a well-defined entropy inequality of the regularized problem.Also,we propose a practical fully discrete finite element approximation of the regularized problem.Next,we use a fixed point theorem to show the existence of the approximate solutions.Moreover,a discrete entropy inequality and some stability bounds on the solutions of regularized problem are derived.In addition,the uniqueness of the fully discrete approximations is preformed.Finally,we discuss the convergence to the fully discrete problem.展开更多
In this paper, we consider the Neumann initial-boundary value problem for the Keller-Segel chemotaxis system with singular sensitivity <img src="Edit_4b941130-fc1e-4c9b-9626-4fd5a1f03836.bmp" alt="&q...In this paper, we consider the Neumann initial-boundary value problem for the Keller-Segel chemotaxis system with singular sensitivity <img src="Edit_4b941130-fc1e-4c9b-9626-4fd5a1f03836.bmp" alt="" />(0.1)<br /> <p> is considered in a bounded domain with smooth boundary, Ω ⊂R<sup><i>n</i></sup> (<i>n</i> ≥ 1), where <i>d</i><sub>1</sub> > 0, <i>d</i><sub>2</sub> > 0 with parameter <i>χ</i> ∈ R. When <i>d</i><sub>1</sub> = <i>d</i><sub>2</sub> + <i>χ</i>, satisfying for all initial data 0 ≤ <i>n</i><sub>0</sub> ∈ <i>C</i><sup>0</sup><img src="Edit_4898c7a9-f047-4856-b9ad-8d42ecf262a2.bmp" alt="" /> and 0 < <i>v</i><sub>0</sub>∈ <i>W</i><sup>1,∞</sup> (Ω), we prove that the problem possesses a unique global classical solution which is uniformly bounded in Ω × (0, ∞). </p>展开更多
In this paper,we study the shock waves for a mixed-type system from chemotaxis.We are concerned with the jump conditions for the left state which is located in the elliptical region and the right state in the hyperbol...In this paper,we study the shock waves for a mixed-type system from chemotaxis.We are concerned with the jump conditions for the left state which is located in the elliptical region and the right state in the hyperbolic region.Under the generalized entropy conditions,we find that there are different shock wave structures for different parameters.To guarantee the uniqueness of the solutions,we obtain the admissible shock waves which satisfy the generalized entropy condition in both parameters.Finally,we construct the Riemann solutions in some solvable regions.展开更多
The singular convergence of a chemotaxis-fluid system modeling coral fertilization is justified in spatial dimension three.More precisely,it is shown that a solution of parabolic-parabolic type chemotaxis-fluid system...The singular convergence of a chemotaxis-fluid system modeling coral fertilization is justified in spatial dimension three.More precisely,it is shown that a solution of parabolic-parabolic type chemotaxis-fluid system modeling coral fertilization■converges to that of the parabolic-elliptic type chemotaxis-fluid system modeling coral fertiliz ation■in a certain Fourier-Herz space asε^(-1)→0.展开更多
In this paper,we consider the quasilinear chemotaxis system of parabolicelliptic type■.under homogeneous Neumann boundary conditions in a smooth bounded domain■n≥1.The nonlinear diffusivity D(ζ)and chemosensitivit...In this paper,we consider the quasilinear chemotaxis system of parabolicelliptic type■.under homogeneous Neumann boundary conditions in a smooth bounded domain■n≥1.The nonlinear diffusivity D(ζ)and chemosensitivity f(ζ)as well as nonlinear signal production g(ζ)are supposed to extend the prototypes■We proved that if m+k+l>1+2/n,then there exists nonnegative radially symmetric initial data uo such that the corresponding solutions blow up in finite time.However,the system admits a global bounded classical solution for arbitrary initial datum when m+k+l<1+2/n.展开更多
In this paper,we consider the fully parabolic Chemotaxis system with the general logistic source{ut=Δ(γ(v)u)+λu-μu^(k),x∈Ω,t>0,vt=△v+wz,x∈Ω,t>0,wt=-wz,x∈Ω,t>0,zt=△z-z+u,x∈Ω,t>0 whereΩ⊂ℝn(n≥...In this paper,we consider the fully parabolic Chemotaxis system with the general logistic source{ut=Δ(γ(v)u)+λu-μu^(k),x∈Ω,t>0,vt=△v+wz,x∈Ω,t>0,wt=-wz,x∈Ω,t>0,zt=△z-z+u,x∈Ω,t>0 whereΩ⊂ℝn(n≥1)is a smooth and bounded domain,λ≥0,μ≥0,κ>1,and the motility function satisfies thatγ(v)∈C3([0,∞)),γ(v)>0,γ′(v)≤0 for all v≥0.Considering the Neumann boundary condition,we obtain the global boundedness of solutions if one of the following conditions holds:(i)λ=μ=0,1≤nλ3;(ii)λ>0,μ>0,combined withκ>1,1≤n≤3 or k>n+2/4,,n>3.Moreover,we prove that the solution (u, v, w, z) exponentially converges to the constant steady state ((λ/μ)1/k-1,∫Ωv0dx+∫Ωw0dx/|Ω|,0,(λ/μ)1/k-1).展开更多
In this paper,we explore bound preserving and high-order accurate local discontinuous Galerkin(LDG)schemes to solve a class of chemotaxis models,including the classical Keller-Segel(KS)model and two other density-depe...In this paper,we explore bound preserving and high-order accurate local discontinuous Galerkin(LDG)schemes to solve a class of chemotaxis models,including the classical Keller-Segel(KS)model and two other density-dependent problems.We use the convex splitting method,the variant energy quadratization method,and the scalar auxiliary variable method coupled with the LDG method to construct first-order temporal accurate schemes based on the gradient flow structure of the models.These semi-implicit schemes are decoupled,energy stable,and can be extended to high accuracy schemes using the semi-implicit spectral deferred correction method.Many bound preserving DG discretizations are only worked on explicit time integration methods and are difficult to get high-order accuracy.To overcome these difficulties,we use the Lagrange multipliers to enforce the implicit or semi-implicit LDG schemes to satisfy the bound constraints at each time step.This bound preserving limiter results in the Karush-Kuhn-Tucker condition,which can be solved by an efficient active set semi-smooth Newton method.Various numerical experiments illustrate the high-order accuracy and the effect of bound preserving.展开更多
In this paper,we study the asymptotic behavior of solutions to a quasilinear fully parabolic chemotaxis system with indirect signal production and logistic source{ut=■·(D(u)■u)-■·(S(u)■v)+b-μur,x∈Ω,t&...In this paper,we study the asymptotic behavior of solutions to a quasilinear fully parabolic chemotaxis system with indirect signal production and logistic source{ut=■·(D(u)■u)-■·(S(u)■v)+b-μur,x∈Ω,t>0,vt=Δv+a1v+b1w,x∈Ω,t>0,wt=Δw-a2w+b2u,x∈Ω,t>0 under homogeneous Neumann boundary conditions in a smooth bounded domainΩ■R^(N)(N≥1),where b≥0,γ≥1,ai≥1,μ,bi>0(i=1,2,D,S∈C^(2)([0,∞))fulfilling D(S)≥a0(s+1)^(-a),0≤S(s)≤b0(s+1)^(β)for all s≥0,where a0,b0>0 and a,β≤R are constants.The pur purpose of this paper is to prove that if b≥0 andμ>0 sufficiently large,the globally bounded solution(u,v,w)with nonnegative initial data(u0,v0,w0)satisfies||u(·,t)-(b/μ)^(1/γ)L∞(Ω)+||V(·,t)+b1b2/a1a2(b/μ)^(1/γ)||L∞(Ω)+||w(·,t)+b2/a2(b/μ)^(1/γ)||L∞(Ω)→0ast→∞.展开更多
In this article, the globally bounded in-time pointwise estimate of solutions to the simplified Keller-Segel system modelling chemotaxis are derived. Moreover, a local existence theorem is obtained.
In this paper we prove the local well-posedness of strong solutions to a chemotaxisshallow water system with initial vacuum in a bounded domainΩ■R^(2)without the standard compatibility condition for the initial data...In this paper we prove the local well-posedness of strong solutions to a chemotaxisshallow water system with initial vacuum in a bounded domainΩ■R^(2)without the standard compatibility condition for the initial data.This improves some results obtained in[J.Differential Equations 261(2016),6758-6789].展开更多
In this paper,we use contraction mapping principle and operator-theoretic approach to establish local solvability of the elliptic-parabolic(hyperbolic)Type Chemotaxis System.In add让ion,global solvabil让y of the syste...In this paper,we use contraction mapping principle and operator-theoretic approach to establish local solvability of the elliptic-parabolic(hyperbolic)Type Chemotaxis System.In add让ion,global solvabil让y of the systems is considered by some uniform estimates.展开更多
This paper considers the following quasilinear chemo-taxis system with indirect signal production and generalized logistic source{u_(t)=▽·(▽(u)▽u)-▽·(S(u)▽v)+μ(u-u^(Y)),x∈Ω,t>0 O=△v-v+w,x∈Ω,t&g...This paper considers the following quasilinear chemo-taxis system with indirect signal production and generalized logistic source{u_(t)=▽·(▽(u)▽u)-▽·(S(u)▽v)+μ(u-u^(Y)),x∈Ω,t>0 O=△v-v+w,x∈Ω,t>0 w_(t)=-δw+u,x∈Ω,t>0 under homogeneous Neumann boundary conditions in a smooth bounded domainΩ■R^(n)(n≥1),where the parametersμ,δ>0 andγ>1,the functions D(u)and S(u)are supposed to be smooth fulfilling D(u)≥C_(D)(u+1)^(-a)and S(u)≤C_(S)u(u+1)^(β-1)for all u≥0 with C D,α,β∈R and.It is proved that the corresponding initial-boundary value problem possesses a global bounded classical solution ifα+2β<γ-1.Moreover,ifμis suitably large,the asymptotic behavior and convergence rates are also been considered.展开更多
This paper is concerned with the well-posedness and large-time behavior of a two-dimensional PDE-ODE hybrid chemotaxis system describing the initiation of tumor angiogenesis. We first transform the system via a Cole-H...This paper is concerned with the well-posedness and large-time behavior of a two-dimensional PDE-ODE hybrid chemotaxis system describing the initiation of tumor angiogenesis. We first transform the system via a Cole-Hopf type transformation into a parabolic-hyperbolic system and then show that the solution to the transformed system converges to a constant equilibrium state as time tends to infinity. Finally we reverse the Cole-Hopf transformation and obtain the relevant results for the pre-transformed PDE-ODE hybrid system.In contrast to the existing related results, where continuous initial data is imposed, we are able to prove the asymptotic stability for discontinuous initial data with large oscillations. The key ingredient in our proof is the use of the so-called "effective viscous flux", which enables us to obtain the desired energy estimates and regularity. The technique of the "effective viscous flux" turns out to be a very useful tool to study chemotaxis systems with initial data having low regularity and was rarely(if not) used in the literature for chemotaxis models.展开更多
In this paper,we discuss the local existence of weak solutions for a parabolic system modelling chemotaxis with memory term,and we show the finite-time blowup and chemotactic collapse for this system.The main methods ...In this paper,we discuss the local existence of weak solutions for a parabolic system modelling chemotaxis with memory term,and we show the finite-time blowup and chemotactic collapse for this system.The main methods we used are the fixed point theorem and the semigroup theory.展开更多
This paper deals with the Neumann initial-boundary value problem for a classical chemotaxis system with signal consumption in a disk.In contrast to previous studies which have established a comprehensive theory of glo...This paper deals with the Neumann initial-boundary value problem for a classical chemotaxis system with signal consumption in a disk.In contrast to previous studies which have established a comprehensive theory of global classical solutions for suitably regular nonnegative initial data,the focus in the present work is on the question to which extent initially prescribed singularities can be regularized despite the presence of the nonlinear cross-diffusive interaction.The main result in this paper asserts that at least in the framework of radial solutions immediate regularization occurs under an essentially optimal condition on the initial distribution of the population density.More precisely,it will turn out that for any radially symmetric initial data belonging to the space of regular signed Borel measures for the population density and to L^(2) for the signal density,there exists a classical solution to the Neumann initial-boundary value problem,which is smooth and approaches the given initial data in an appropriate trace sense.展开更多
基金This work is supported by the Youth Doctor Science and Technology Talent Training Project of Xinjiang Uygur Autonomous Region(2017Q087).
文摘This article considers the following higher-dimensional quasilinear parabolic-parabolic-ODE chemotaxis system with generalized Logistic source and homogeneous Neumann boundary conditions{ut=∇⋅(D(u)∇u)−∇⋅(S(u)∇v)+f(u),x∈Ω,t>0 vt=Δv+w−v,x∈Ω,t>0,wt=u−w,x∈Ω,t>0,in a bounded domainΩ⊂R^n(n≥2)with smooth boundary ∂Ω,where the diffusion coefficient D(u)and the chemotactic sensitivity function S(u)are supposed to satisfy D(u)≥M1(u+1)^−αand S(u)≤M2(u+1)^β,respectively,where M1,M2>0 and α,β∈R.Moreover,the logistic source f(u)is supposed to satisfy f(u)≤a−μu^γ with μ>0,γ≥1,and a≥0.Asα+2β<γ−1+2γ/n,we show that the solution of the above chemotaxis system with sufficiently smooth nonnegative initial data is uniformly bounded.
基金Supported by the National Natural Science Foundation of China(11131005)the Fundamental Research Funds for the Central Universities(2014201020202)
文摘In this paper, we use contraction mapping principle, operator-theoretic approach and some uniform estimates to establish local solvability of the parabolic-hyperbolic type chemotaxis system with fixed boundary in 1-dimensional domain. In addition, local solvability of the free boundary problem is considered by straightening the free boundary.
基金supported by the Young Scholars Development Fund of SWPU(202199010087)the Scientific Research Starting Project of SWPU(2021QHZ016)+2 种基金supported by the National Natural Science Foundation of China(11771062and 11971082)the Fundamental Research Funds for the Central Universities(2019CDJCYJ001)Chongqing Key Laboratory of Analytic Mathematics and Applications。
文摘This work explores the predator-prey chemotaxis system with two chemicals {u_(t) = Δu + ∇ ・ (u∇v) + μ_(1)u(1 − u − α_(1)w), x ∈ Ω, t > 0,v_(t )= Δv −α_(1)v + β_(1)w, x ∈ Ω, t > 0,w_(t) = Δw − ξ∇ ・ (w∇z) + μ_(2)w(1 + α_(2)u − w), x ∈ Ω, t > 0,z_(t) =Δz −α_(2)z +β_(2)u, x ∈ Ω, t > 0, in an arbitrary smooth bounded domainΩ■R^(n) under homogeneous Neumann boundary conditions.The parameters in the system are positive.We first prove that if n≤3,the corresponding initial-boundary value problem admits a unique global bounded classical solution,under the assumption thatχ,ξ,μ_(i),a_(i),α_(i) andβ_(i)(i=1,2)satisfy some suitable conditions.Subsequently,we also analyse the asymptotic behavior of solutions to the above system and show that·when a_(1)<1 and bothμ1/χ^(2) andμ2/ξ^(2) are sufficiently large,the global solution(u,v,w,z)of this system exponentially converges to(1-a_(1)/1+a_(1)a_(2),β_(1)(1+a_(2))/α_(1)(1+a_(1)a_(2)),1+a_(2)/1+a_(1)a_(2),β_(2)(1-a_(1))/α_(2)(1+a_(1)a_(2)))as t→∞;·when a1>1 andμ_(2)/ξ_(2) is sufficiently large,the global bounded classical solution(u,v,w,z)of this system exponentially converges to(0,α_(1)/β_(1),1,0)as t→∞;·when a1=1 andμ_(2)/ξ_(2) is sufficiently large,the global bounded classical solution(u,v,w,z)of this system polynomially converges to(0,α_(1)/β_(1),1,0)as t→∞.
基金The NSF(11301419)of Chinathe Meritocracy Research Funds(17YC382)of China West Normal University
文摘This paper is devoted to dealing with the parabolic-elliptic-elliptic attraction-repulsion chemotaxis system.We aim to understand the competition among the repulsion,the attraction,the nonlinear productions and give conditions of global existence and blow-up for the two-dimensional attraction-repulsion chemotaxis system。
文摘In Hashim and Harfash(Appl.Math.Comput.2021),using a finite element method,the attraction-repulsion chemotaxis model(P)in space is discretised;finite differences were used to do the same in time.Furthermore,the existence of a global weak solution to the system(PΔt M)was demonstrated by means of analysis of the convergence of the fully discrete approximate problem(P h,Δt M,).Moreover,the functions{U,Z,V}were proved to represent a global weak solution to the system(PΔt M)by means of a passage to the limit,h→0 of the approximate system.This paper’s purpose is to demonstrate that the solutions can be bounded,independent of M.The analysis contained in this paper illustrates the idea of the existence of weak solutions to the model(P),that requires passing to the limits,Δt→0+and M→∞.The time stepΔt is subsequently linked to the cutoff parameter M>1 by positing a demand thatΔt=o(M−1),as M→∞,with the result that the cutoff parameter becomes the only parameter in the problem(PΔt M).The solutions can be bounded,independ-ent of M,with the use of special energy estimates,as demonstrated herein.Then,these M-independent bounds on the relative entropy are employed with the purpose of deriving M-independent bounds on the time-derivatives.Additionally,compactness arguments were utilised to explore the convergence of the finite element approximate problem.The conclu-sion was that a weak solution for(P)existed.Finally,we introduced the error estimate and the implicit scheme was used to perform simulations in one and two space dimensions.
文摘In this paper,a finite element scheme for the attraction-repulsion chemotaxis model is analyzed.We introduce a regularized problem of the truncated system.Then we obtain some a priori estimates of the regularized functions,independent of the regularization parameter,via deriving a well-defined entropy inequality of the regularized problem.Also,we propose a practical fully discrete finite element approximation of the regularized problem.Next,we use a fixed point theorem to show the existence of the approximate solutions.Moreover,a discrete entropy inequality and some stability bounds on the solutions of regularized problem are derived.In addition,the uniqueness of the fully discrete approximations is preformed.Finally,we discuss the convergence to the fully discrete problem.
文摘In this paper, we consider the Neumann initial-boundary value problem for the Keller-Segel chemotaxis system with singular sensitivity <img src="Edit_4b941130-fc1e-4c9b-9626-4fd5a1f03836.bmp" alt="" />(0.1)<br /> <p> is considered in a bounded domain with smooth boundary, Ω ⊂R<sup><i>n</i></sup> (<i>n</i> ≥ 1), where <i>d</i><sub>1</sub> > 0, <i>d</i><sub>2</sub> > 0 with parameter <i>χ</i> ∈ R. When <i>d</i><sub>1</sub> = <i>d</i><sub>2</sub> + <i>χ</i>, satisfying for all initial data 0 ≤ <i>n</i><sub>0</sub> ∈ <i>C</i><sup>0</sup><img src="Edit_4898c7a9-f047-4856-b9ad-8d42ecf262a2.bmp" alt="" /> and 0 < <i>v</i><sub>0</sub>∈ <i>W</i><sup>1,∞</sup> (Ω), we prove that the problem possesses a unique global classical solution which is uniformly bounded in Ω × (0, ∞). </p>
基金the National Natural Science Foundation of China(11771442)。
文摘In this paper,we study the shock waves for a mixed-type system from chemotaxis.We are concerned with the jump conditions for the left state which is located in the elliptical region and the right state in the hyperbolic region.Under the generalized entropy conditions,we find that there are different shock wave structures for different parameters.To guarantee the uniqueness of the solutions,we obtain the admissible shock waves which satisfy the generalized entropy condition in both parameters.Finally,we construct the Riemann solutions in some solvable regions.
基金Supported by the NSFC(12161041,12001435 and12071197)the training program for academic and technical leaders of major disciplines in Jiangxi Province(20204BCJL23057)+2 种基金the Natural Science Foundation of Jiangxi Province(20212BAB201008)the Educational Commission Science Programm of Jiangxi Province(GJJ190272)Natural Science Foundation of Shandong Province(ZR2021MA031)。
文摘The singular convergence of a chemotaxis-fluid system modeling coral fertilization is justified in spatial dimension three.More precisely,it is shown that a solution of parabolic-parabolic type chemotaxis-fluid system modeling coral fertilization■converges to that of the parabolic-elliptic type chemotaxis-fluid system modeling coral fertiliz ation■in a certain Fourier-Herz space asε^(-1)→0.
基金supported by the Research and Innovation Team of China West Normal University(CXTD2020-5).
文摘In this paper,we consider the quasilinear chemotaxis system of parabolicelliptic type■.under homogeneous Neumann boundary conditions in a smooth bounded domain■n≥1.The nonlinear diffusivity D(ζ)and chemosensitivity f(ζ)as well as nonlinear signal production g(ζ)are supposed to extend the prototypes■We proved that if m+k+l>1+2/n,then there exists nonnegative radially symmetric initial data uo such that the corresponding solutions blow up in finite time.However,the system admits a global bounded classical solution for arbitrary initial datum when m+k+l<1+2/n.
基金supported by the NSFC(12301260)the Hong Kong Scholars Program(XJ2023002,2023-078)+14 种基金the Double First-Class Construction-Talent Introduction of Southwest University(SWU-KR22037)the Chongqing Post-Doctoral Fund for Staying in Chongqing(2022)partially supported by the NSFC(12271064,11971082)the Chongqing Talent Support Program(cstc2022ycjh-bgzxm0169)the Natural Science Foundation of Chongqing(cstc2021jcyj-msxmX1051)the Fundamental Research Funds for the Central Universities(2020CDJQY-Z001,2019CDJCYJ001)the Key Laboratory of Nonlinear Analysis and its Applications(Chongqing University)Ministry of EducationChongqing Key Laboratory of Analytic Mathematics and Applicationssupported by the NSFC(12301261)the Scientific Research Starting Project of SWPU(2021QHZ016)the Sichuan Science and Technology Program(2023NSFSC1365)the Nanchong Municipal Government-Universities Scientific Cooperation Project(SXHZ045)supported by the China Scholarship Council(202206050060)the Graduate Research and Innovation Foundation of Chongqing(CYB22044)。
文摘In this paper,we consider the fully parabolic Chemotaxis system with the general logistic source{ut=Δ(γ(v)u)+λu-μu^(k),x∈Ω,t>0,vt=△v+wz,x∈Ω,t>0,wt=-wz,x∈Ω,t>0,zt=△z-z+u,x∈Ω,t>0 whereΩ⊂ℝn(n≥1)is a smooth and bounded domain,λ≥0,μ≥0,κ>1,and the motility function satisfies thatγ(v)∈C3([0,∞)),γ(v)>0,γ′(v)≤0 for all v≥0.Considering the Neumann boundary condition,we obtain the global boundedness of solutions if one of the following conditions holds:(i)λ=μ=0,1≤nλ3;(ii)λ>0,μ>0,combined withκ>1,1≤n≤3 or k>n+2/4,,n>3.Moreover,we prove that the solution (u, v, w, z) exponentially converges to the constant steady state ((λ/μ)1/k-1,∫Ωv0dx+∫Ωw0dx/|Ω|,0,(λ/μ)1/k-1).
文摘In this paper,we explore bound preserving and high-order accurate local discontinuous Galerkin(LDG)schemes to solve a class of chemotaxis models,including the classical Keller-Segel(KS)model and two other density-dependent problems.We use the convex splitting method,the variant energy quadratization method,and the scalar auxiliary variable method coupled with the LDG method to construct first-order temporal accurate schemes based on the gradient flow structure of the models.These semi-implicit schemes are decoupled,energy stable,and can be extended to high accuracy schemes using the semi-implicit spectral deferred correction method.Many bound preserving DG discretizations are only worked on explicit time integration methods and are difficult to get high-order accuracy.To overcome these difficulties,we use the Lagrange multipliers to enforce the implicit or semi-implicit LDG schemes to satisfy the bound constraints at each time step.This bound preserving limiter results in the Karush-Kuhn-Tucker condition,which can be solved by an efficient active set semi-smooth Newton method.Various numerical experiments illustrate the high-order accuracy and the effect of bound preserving.
基金The paper is supported by the National Science Foundation of China(11301419)the Meritocracy Research Funds of China West Normal University[17YC382].
文摘In this paper,we study the asymptotic behavior of solutions to a quasilinear fully parabolic chemotaxis system with indirect signal production and logistic source{ut=■·(D(u)■u)-■·(S(u)■v)+b-μur,x∈Ω,t>0,vt=Δv+a1v+b1w,x∈Ω,t>0,wt=Δw-a2w+b2u,x∈Ω,t>0 under homogeneous Neumann boundary conditions in a smooth bounded domainΩ■R^(N)(N≥1),where b≥0,γ≥1,ai≥1,μ,bi>0(i=1,2,D,S∈C^(2)([0,∞))fulfilling D(S)≥a0(s+1)^(-a),0≤S(s)≤b0(s+1)^(β)for all s≥0,where a0,b0>0 and a,β≤R are constants.The pur purpose of this paper is to prove that if b≥0 andμ>0 sufficiently large,the globally bounded solution(u,v,w)with nonnegative initial data(u0,v0,w0)satisfies||u(·,t)-(b/μ)^(1/γ)L∞(Ω)+||V(·,t)+b1b2/a1a2(b/μ)^(1/γ)||L∞(Ω)+||w(·,t)+b2/a2(b/μ)^(1/γ)||L∞(Ω)→0ast→∞.
基金Supported by the NSF of Jiangxi Province, the NSFC (10225105, 10671023) and a CAEP grant
文摘In this article, the globally bounded in-time pointwise estimate of solutions to the simplified Keller-Segel system modelling chemotaxis are derived. Moreover, a local existence theorem is obtained.
基金supported by NSFC(11971234)supported in part by NSFC(11671193)A Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions。
文摘In this paper we prove the local well-posedness of strong solutions to a chemotaxisshallow water system with initial vacuum in a bounded domainΩ■R^(2)without the standard compatibility condition for the initial data.This improves some results obtained in[J.Differential Equations 261(2016),6758-6789].
文摘In this paper,we use contraction mapping principle and operator-theoretic approach to establish local solvability of the elliptic-parabolic(hyperbolic)Type Chemotaxis System.In add让ion,global solvabil让y of the systems is considered by some uniform estimates.
基金Supported by the Science and Technology Research Project of Chongqing Education Commission(KJQN202000618)。
文摘This paper considers the following quasilinear chemo-taxis system with indirect signal production and generalized logistic source{u_(t)=▽·(▽(u)▽u)-▽·(S(u)▽v)+μ(u-u^(Y)),x∈Ω,t>0 O=△v-v+w,x∈Ω,t>0 w_(t)=-δw+u,x∈Ω,t>0 under homogeneous Neumann boundary conditions in a smooth bounded domainΩ■R^(n)(n≥1),where the parametersμ,δ>0 andγ>1,the functions D(u)and S(u)are supposed to be smooth fulfilling D(u)≥C_(D)(u+1)^(-a)and S(u)≤C_(S)u(u+1)^(β-1)for all u≥0 with C D,α,β∈R and.It is proved that the corresponding initial-boundary value problem possesses a global bounded classical solution ifα+2β<γ-1.Moreover,ifμis suitably large,the asymptotic behavior and convergence rates are also been considered.
基金supported by Academy of Mathematics and Systems Science,Chinese Academy of Sciences and the Joint Laboratory of Applied Mathematics in the Hong Kong Polytechnic University where he was a postdoctoral fellow,National Natural Science Foundation of China(Grant No.11901115)Natural Science Foundation of Guangdong Province(Grant No.2019A1515010706)+4 种基金Guangdong University of Technology(Grant No.220413228)supported by the Hong Kong Research Grant Council General Research Fund(Grant No.Poly U 153031/17P)the Hong Kong Polytechnic University(Grant No.ZZHY)supported by National Natural Science Foundation of China(Grant Nos.11771150,11831003 and 11926346)Guangdong Basic and Applied Basic Research Foundation(Grant No.2020B1515310015)。
文摘This paper is concerned with the well-posedness and large-time behavior of a two-dimensional PDE-ODE hybrid chemotaxis system describing the initiation of tumor angiogenesis. We first transform the system via a Cole-Hopf type transformation into a parabolic-hyperbolic system and then show that the solution to the transformed system converges to a constant equilibrium state as time tends to infinity. Finally we reverse the Cole-Hopf transformation and obtain the relevant results for the pre-transformed PDE-ODE hybrid system.In contrast to the existing related results, where continuous initial data is imposed, we are able to prove the asymptotic stability for discontinuous initial data with large oscillations. The key ingredient in our proof is the use of the so-called "effective viscous flux", which enables us to obtain the desired energy estimates and regularity. The technique of the "effective viscous flux" turns out to be a very useful tool to study chemotaxis systems with initial data having low regularity and was rarely(if not) used in the literature for chemotaxis models.
文摘In this paper,we discuss the local existence of weak solutions for a parabolic system modelling chemotaxis with memory term,and we show the finite-time blowup and chemotactic collapse for this system.The main methods we used are the fixed point theorem and the semigroup theory.
基金supported by the Applied Fundamental Research Program of Sichuan Province(Grant No.2018JY0503)Xihua University Scholars Training Programsupported by the Deutsche Forschungsgemeinschaft in the context of the project Emergence of Structures and Advantages in Cross-Diffusion Systems(Grant No.411007140,GZ:WI 3707/5-1)+2 种基金supported by National Natural Science Foundation of China(Grant Nos.11971093 and 11771045)the Applied Fundamental Research Program of Sichuan Province(Grant No.20YYJC4388)the Fundamental Research Funds for the Central Universities(Grant No.ZYGX2019J096)。
文摘This paper deals with the Neumann initial-boundary value problem for a classical chemotaxis system with signal consumption in a disk.In contrast to previous studies which have established a comprehensive theory of global classical solutions for suitably regular nonnegative initial data,the focus in the present work is on the question to which extent initially prescribed singularities can be regularized despite the presence of the nonlinear cross-diffusive interaction.The main result in this paper asserts that at least in the framework of radial solutions immediate regularization occurs under an essentially optimal condition on the initial distribution of the population density.More precisely,it will turn out that for any radially symmetric initial data belonging to the space of regular signed Borel measures for the population density and to L^(2) for the signal density,there exists a classical solution to the Neumann initial-boundary value problem,which is smooth and approaches the given initial data in an appropriate trace sense.