18 research outputs found
Global asymptotic stability for semilinear equations via Thompson's metric
In ordered Banach spaces we prove the global asymptotic stability of the unique strictly positive equilibrium of the semilinear equation uⲠ= Au + ę(u), if A is the generator of a positive and exponentially stable Câ-semigroup and ę is a contraction with respect to Thompson's metric. The given estimates show that convergence holds with a uniform exponential rate.peerReviewe
Maximal L p -regularity for the Laplacian on Lipschitz domains
We consider the Laplacian with Dirichlet or Neumann boundary
conditions on bounded Lipschitz domains ?, both with the following two domains of
definition:D1(?) = {u ? W1,p(?) : ?u ? Lp(?), Bu = 0}, orD2(?) = {u ? W2,p(?) :
Bu = 0}, where B is the boundary operator.We prove that, under certain restrictions
on the range of p, these operators generate positive analytic contraction semigroups
on Lp(?) which implies maximal regularity for the corresponding Cauchy problems.
In particular, if ? is bounded and convex and 1 < p ? 2, the Laplacian with domain
D2(?) has the maximal regularity property, as in the case of smooth domains. In the
last part,we construct an example that proves that, in general, the DirichletâLaplacian
with domain D1(?) is not even a closed operator
Global Asymptotic Stability for Semilinear Equations via Thompsonâs Metric
In ordered Banach spaces we prove the global asymptotic stability of the unique
strictly positive equilibrium of the semilinear equation u
Ⲡ= Au + f(u), if A is the generator
of a positive and exponentially stable C0-semigroup and f is a contraction with respect
to Thompsonâs metric. The given estimates show that convergence holds with a uniform
exponential rate
Global asymptotic stability for semilinear equations via Thompson's metric
In ordered Banach spaces we prove the global asymptotic stability of the unique strictly positive equilibrium of the semilinear equation uⲠ= Au + ę(u), if A is the generator of a positive and exponentially stable Câ-semigroup and ę is a contraction with respect to Thompson's metric. The given estimates show that convergence holds with a uniform exponential rate.peerReviewe
Contraction semigroups on Lâ(R)
If X is a non-degenerate vector field on R and H = âX 2 we examine conditions for the closure of H to generate a continuous semigroup on L â which extends to the Lp-spaces. We give an example which cannot be extended and an example which extends but for which the real part of the generator on L2 is not lower semibounded