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The Random Attractor Of The Development Equation On The Change Domain

Posted on:2020-12-25Degree:DoctorType:Dissertation
Country:ChinaCandidate:F Z LiFull Text:PDF
GTID:1360330599957366Subject:Probability theory and mathematical statistics
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In this thesis,we study the dynamics of stochastic evolution equation on the vary-ing domains.We mainly discuss two kinds of varying domains:thin domain and expansion domain.Thin domain refers to a domain collapses onto a lower dimensional spatial do-main.At present,there are some results on the thin domain problem in the literature.The specific problems considered in this thesis are to prove the existence and the con-vergence?i.e.upper semi-continuity?of bi-spatial random attractors in regular space when the domain degenerates to the lower dimensional spatial domain.The expansion domain means that a bounded domain extended to an unbound-ed domain.The problem of expansion domain is a new subject in this thesis,which we mainly studies the existence of random attractor and upper semi-continuity when bounded domain attractor approaches to the unbounded domain for stochastic evolu-tion equation defined on a family of expanding domains.More precisely,the main objective and innovations of this thesis are as follows:First,we show the existence of bi-spatial random attractor and the convergence in regular space when the domain collapses to the lower dimensional spatial domain for stochastic reaction-diffusion equation on a thin domain.The measurability for each attractor A???is the thin direction measure?in L2and Lpspaces are obtained and borrowing the methods of symbolical truncation and spatial split,we prove the attractiveness and compactness of A?in Lp.Furthermore,we prove that A?converges to the attractor of lower dimensional domain under the topology of Lp,when measure converges to zero in thin direction.Second,we prove the existence of random attractor both in p-order Lebesgue s-pace and Sobolev space as well as upper semi-continuity under the p-norm for reaction-diffusion equation with a general multiplicative noise defined on a thin domain.Unlike the system with additive noise,we need to make different assumptions about the sys-tem with a general multiplicative noise to obtain different Lusin continuity in sample and uniform estimates of solutions.On the other hand,we further apply the spec-tral decomposition to obtain the uniform estimates and asymptotic compactness of the cocycle in a Sobolev space.Third,we consider both the?L2,H1?-continuity with respect to the initial da-ta and?L2,H1?-random attractor of the stochastic reaction-diffusion equation on a thin domain,where the nonlinearity can be decomposed into two functions with?p,q?-growth exponents.By means of a computation method of induction and bootstrap tech-nique,it is shown that the difference of solutions near an initial time is(L2,Lkp-2k+2)-continuously.In particular,by the 2p-2-order integrability,we show the continuity of solution operator from L2to H1when k=2,which we further show the existence of?L2,H1?-random attractor of the stochastic reaction-diffusion system.Fourth,taking the stochastic g-Navier-Stokes equation as an example?refer to re-placing?·?gu?=0 by?·u=0 in the usual NS equation?,we establish a theoretical criterion of the existence and approximation of random attractors on the expansion do-main.Roughly speaking,using the expansion and restriction of functions as well as generalizing the energy-equation method,we show that the sequence of expanding co-cycles are weakly equi-continuous and strongly equi-asymptotically compact,which leads to existence of the null-expansion of corresponding random attractor and upper semi-continuity when unbounded-domain attractor is approximated by the family of bounded-domain attractors.
Keywords/Search Tags:Non-autonomous random dynamical system, bi-spatial attractor, regularity, upper semi-continuity, thin domain, expansion domain
PDF Full Text Request
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