Symmetric subspaces of with large projection constants
We construct k-dimensional (k ≥ 3) subspaces of , with a very simple structure and with projection constant satisfying .
Symmetric subspaces related to certain eigenvalue problems
Symmetrization of functions and principal eigenvalues of elliptic operators
In this paper, we consider shape optimization problems for the principal eigenvalues of second order uniformly elliptic operators in bounded domains of . We first recall the classical Rayleigh-Faber-Krahn problem, that is the minimization of the principal eigenvalue of the Dirichlet Laplacian in a domain with fixed Lebesgue measure. We then consider the case of the Laplacian with a bounded drift, that is the operator , for which the minimization problem is still well posed. Next, we deal with...
Symmetrization of hyperbolic systems with real constant coefficients
Symmetry and concentration behavior of ground state in axially symmetric domains.
Symmetry and monotonicity of solutions to some variational problems in cylinders and annuli.
Symmetry breaking for molecular open systems
Symmetry operators of a Hartree-type equation with quadratic potential.
Synthèse harmonique ultramétrique. Théorie spectrale en analyse ultramétrique
Syntheses of differential games and pseudo-Riccati equations.
System of fractional differential equations with Erdélyi-Kober fractional integral conditions
In this paper we study existence and uniqueness of solutions for a system consisting from fractional differential equations of Riemann-Liouville type subject to nonlocal Erdélyi-Kober fractional integral conditions. The existence and uniqueness of solutions is established by Banach’s contraction principle, while the existence of solutions is derived by using Leray-Schauder’s alternative. Examples illustrating our results are also presented.
System of general variational inequalities involving different nonlinear operators related to fixed point problems and its applications.
System of generalized implicit vector quasivariational inequalities.
Système dynamique à spectre discret et pavage périodique associé à une substitution
On donne une condition combinatoire effective suffisante pour que le sytème dynamique associé à une substitution de type Pisot ait un spectre purement discret. Dans le cas unimodulaire, cette condition est nécessaire dès que la substitution n'a qu'un cobord trivial ; elle est vérifiée si et seulement si le fractal de Rauzy associé à la substitution engendre un pavage auto-similaire et périodique. On en déduit des conditions de connexité des fractals de Rauzy.
Systèmes elliptiques ayant un spectre essentiel
Systems of degenerate differential equations in Banach spaces.
Systems of generalized quasivariational inclusion problems with applications in -spaces.
Systems of reaction-diffusion equations with spatially distributed hysteresis
We study systems of reaction-diffusion equations with discontinuous spatially distributed hysteresis on the right-hand side. The input of the hysteresis is given by a vector-valued function of space and time. Such systems describe hysteretic interaction of non-diffusive (bacteria, cells, etc.) and diffusive (nutrient, proteins, etc.) substances leading to formation of spatial patterns. We provide sufficient conditions under which the problem is well posed in spite of the assumed discontinuity of...
Systems with hysteresis in the feedback loop : existence, regularity and asymptotic behaviour of solutions
An existence and regularity theorem is proved for integral equations of convolution type which contain hysteresis nonlinearities. On the basis of this result, frequency-domain stability criteria are derived for feedback systems with a linear infinite-dimensional system in the forward path and a hysteresis nonlinearity in the feedback path. These stability criteria are reminiscent of the classical circle criterion which applies to static sector-bounded nonlinearities. The class of hysteresis operators...
Systems with hysteresis in the feedback loop: existence, regularity and asymptotic behaviour of solutions
An existence and regularity theorem is proved for integral equations of convolution type which contain hysteresis nonlinearities. On the basis of this result, frequency-domain stability criteria are derived for feedback systems with a linear infinite-dimensional system in the forward path and a hysteresis nonlinearity in the feedback path. These stability criteria are reminiscent of the classical circle criterion which applies to static sector-bounded nonlinearities. The class of hysteresis operators...