# strongly continuous semigroup

## strongly continuous semigroup

[¦strȯŋ·lē kən¦tin·yə·wəs ′sem·i‚grüp]
(mathematics)
A semigroup of bounded linear operators on a Banach space B, together with a bijective mapping T from the positive real numbers onto the semigroup, such that T (0) is the identity operator on B, T (s + t) = T (s) T (t) for any two positive numbers s and t and, for each element x of B, T (t) x is a continuous function of t.
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References in periodicals archive ?
where A : D(A) [subset or equal to] X [right arrow] X is the infinitesimal generator of strongly continuous semigroup of bounded linear operators T(t), t > 0.
[{[B.sub.t]}.sub.t[greater than or equal to]0] is a strongly continuous semigroup. Proof.
One can verify that the family [P.sup.w] = [([P.sup.w.sub.t]).sub.t[greater than or equal to] 0] forms a strongly continuous semigroup of contraction operators on [L.sup.2]([OMEGA]).
Denote by [DELTA] = [[summation].sup.m.sub.j=1]([[partial derivative].sup.2]/[partial derivative][x.sup.2.sub.j]) the Laplace operator, with domain D([DELTA]) = [W.sup.1,2.sub.0](Y) [intersection] [W.sup.2,2.sub.0](Y), which generates a strongly continuous semigroup [mathematical expression not reproducible], where [W.sup.1,2.sub.0](Y) and [W.sup.2,2.sub.0](Y) are the Sobolev spaces with compactly supported sets.
where x(*) the state of the system (1.1) takes values in a Banach space X (state space), the unbounded operator (A,D(A)) generates a [C.sub.0]-semigroup (strongly continuous semigroup) [(T(t)).sub.t[greater than or equal to]0] on X, B is unbounded linear control operators in the sense that it is a bounded linear operator from X to a larger Banach space V [contains] X, i.e.
Motivated by the works of Mustari and Taylor [15,17], we have recently begun to study the mean ergodic theorem under the framework of RN modules [18] to obtain the mean ergodic theorem in the sense of convergence in probability, where we proved the mean ergodic theorem for a strongly continuous semigroup of random unitary operators defined on complete random inner product modules (briefly, complete RIP modules).
Then A generates a strongly continuous semigroup that is analytic, and resolvent operator R(t) can be extracted from this analytic semigroup(see [17]).
where A:D(A) [subset] X [right arrow] X is the infinitesimal generator of a strongly continuous semigroup [{T(t)}.sub.t[greater than or equal to]0], and B: X [right arrow] [??](H, X) is a bounded linear operator.
i) The two-parameter (nonlinear) semiflow [sigma] is continuous if and only if it induces a strongly continuous semigroup [{T(t)}.sub.t[greater than or equal to]0] on X by the formula:
where A generates a strongly continuous semigroup ([e.sup.tA])t [greater than or equal to] 0 on an infinite dimensional Banach space Y (state space) whose norm will be denoted by [parallel].[parallel], B : D(B)([subset] Y) [arrow right] Y is a possibly unbounded linear operator and the control function u(*) denotes the scalar control.
After a short introduction to the theory of strongly continuous semigroups on linear operators on Banach spaces, the authors introduce abstract delay equations on a Banach space X and discuss examples.
van Casteren, Generators of Strongly Continuous Semigroups, Research Notes in Math., Pitman Publishing Limited, London, 1985.

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