Results 31 to 40 of about 722,802 (181)
Almost-periodicity in linear topological spaces and applications to abstract differential equations
International Journal of Mathematics and Mathematical Sciences, 1984 Let E be a complete locally convex space (l.c.s.) and f:R→E a continuous function; then f is said to be almost-periodic (a.p.) if, for every neighbourhood (of the origin in E) U, there exists ℓ=ℓ(U)>0 such that every interval [a,a+ℓ] of the real line ...
Gaston Mandata N'Guerekata
doaj +1 more source
Asymptotic stability of solutions to abstract differential equations [PDF]
, 2010 An evolution problem for abstract differential equations is studied. The typical problem is: $$\dot{u}=A(t)u+F(t,u), \quad t\geq 0; \,\, u(0)=u_0;\quad \dot{u}=\frac {du}{dt}\qquad (*)$$ Here $A(t)$ is a linear bounded operator in a Hilbert space $H ...
Ramm, A. G.
core +4 more sources
Weak Solutions for Time-Fractional Evolution Equations in Hilbert Spaces
Fractal and Fractional, 2021 Our purpose is to introduce a notion of weak solution for a class of abstract fractional differential equations. We point out that the time fractional derivative occurring in the equations is in the sense of the Caputo derivative.
Paola Loreti, Daniela Sforza
doaj +1 more source
Ward Identities for Affine-Virasoro Correlators
, 1992 Generalizing the Knizhnik-Zamolodchikov equations, we derive a hierarchy of non-linear Ward identities for affine-Virasoro correlators. The hierarchy follows from null states of the Knizhnik-Zamolodchikov type and the assumption of factorization, whose ...
Halpern, M. B., Obers, N. A.
core +1 more source
ON ABSTRACT SECOND ORDER DIFFERENTIAL EQUATIONS
Demonstratio Mathematica, 1990 We study the problem \[ u''(t)+Au'(t)+Bu(t)=f(t,u(t)),\tag{1} \] \[ u(0)=\Phi, \qquad u'(0)=\Psi,\tag{2} \] in an arbitrary Banach space \(E\) with norm \(\|\cdot\|\), where \(A\), \(B\) are usually unbounded linear operators in \(E\) and \(f\in C[I\times E,E]\), \(I=[a,b]\), \(a>0\).
openaire +2 more sources
Abstract differential equations and Caputo fractional derivative
Semigroup Forum, 2022 In this work I consider the abstract Cauchy problems with Caputo fractional time derivative of order $ \in(0,1]$, and discuss the continuity of the respective solutions regarding the parameter $ $. I also present a study about the continuity of the Mittag-Leffler families of operators (for $ \in(0,1]$), induced by sectorial operators.
openaire +3 more sources
Abstract stochastic integrodifferential delay equations [PDF]
International Journal of Stochastic Analysis, 2005 We investigate a class of abstract stochastic integrodifferential delay equations dependent upon a family of probability measures in a separable Hilbert space. We establish the existence and uniqueness of a mild solution, along with various continuous dependence estimates and Markov (weak and strong) properties of this solution.
Keck, David N., McKibben, Mark A.
openaire +2 more sources
Effect of blood perfusion on thermal therapy in multilayer skin by semigroups approach [PDF]
Journal of Mahani Mathematical ResearchA semi-analytical solution is proposed for the bioheat equation, which includes the epidermis, dermis, and hypodermis layers in the presence of a surface pulsed heat source.
Ghasem Abbasi, Soheila Khishtandar
doaj +1 more source
ABSTRACT VARIABLE DOMAIN HYPERBOLIC DIFFERENTIAL EQUATIONS
Demonstratio Mathematica, 2004 Summary: An abstract problem is studied for a class of linear hyperbolic differential equations with variable domain and non-local boundary conditions. Existence and uniqueness of the strong solution are proved.
openaire +2 more sources
Random fixed points and random differential inclusions
International Journal of Mathematics and Mathematical Sciences, 1988 In this paper, first, we study random best approximations to random sets, using fixed point techniques, obtaining this way stochastic analogues of earlier deterministic results by Browder-Petryshyn, KyFan and Reich. Then we prove two fixed point theorems
Nikolaos S. Papageorgiou
doaj +1 more source