Results 1  10
of
18
On the relation between elliptic and parabolic Harnack inequalities
, 2001
"... We show that, if a certain Sobolev inequality holds, then a scaleinvariant elliptic Harnack inequality suces to imply its a priori stronger parabolic counterpart. Neither the relative Sobolev inequality nor the elliptic Harnack inequality alone suces to imply the parabolic Harnack inequality in que ..."
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Cited by 27 (3 self)
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We show that, if a certain Sobolev inequality holds, then a scaleinvariant elliptic Harnack inequality suces to imply its a priori stronger parabolic counterpart. Neither the relative Sobolev inequality nor the elliptic Harnack inequality alone suces to imply the parabolic Harnack inequality in question; both are necessary conditions. As an application, we show the equivalence between parabolic Harnack inequality for on M , (i.e., for @ t + ) and elliptic Harnack inequality for @ 2 t + on R M . 1
On Random Walks on Wreath Products
 Ann. Probab
, 2001
"... Wreath products are a type of semidirect products. They play an important role in group theory. This paper studies the basic behavior of simple random walks on such groups and shows that these walks have interesting, somewhat exotic behaviors. The crucial fact is that the probability of return to th ..."
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Cited by 20 (1 self)
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Wreath products are a type of semidirect products. They play an important role in group theory. This paper studies the basic behavior of simple random walks on such groups and shows that these walks have interesting, somewhat exotic behaviors. The crucial fact is that the probability of return to the starting point of certain walks on wreath products is closely related to some functionals of the local times of a walk taking place on a simpler factor group.
L p spectral theory of higherorder elliptic differential operators
 Bull. London Math. Soc
, 1997
"... 2. Eigenvalues and eigenfunctions 516 2.1 Spectral asymptotics 516 2.2 The isoperimetric problem 518 ..."
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Cited by 12 (1 self)
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2. Eigenvalues and eigenfunctions 516 2.1 Spectral asymptotics 516 2.2 The isoperimetric problem 518
An asymptotic dimension for metric spaces, and the 0th NovikovShubin invariant
"... A nonnegative number d∞, called asymptotic dimension, is associated with any metric space. Such number detects the asymptotic properties of the space (being zero on bounded metric spaces), fulfills the properties of a dimension, and is invariant under rough isometries. It is then shown that for a cl ..."
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Cited by 6 (5 self)
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A nonnegative number d∞, called asymptotic dimension, is associated with any metric space. Such number detects the asymptotic properties of the space (being zero on bounded metric spaces), fulfills the properties of a dimension, and is invariant under rough isometries. It is then shown that for a class of open manifolds with bounded geometry the asymptotic dimension coincides with the 0th NovikovShubin number α0 defined in a previous paper [D. Guido, T. Isola, J. Funct. Analysis, 176 (2000)]. Thus the dimensional interpretation of α0 given in the mentioned paper in the framework of noncommutative geometry is established on metrics grounds. Since the asymptotic dimension of a covering manifold coincides with the polynomial growth of its covering group, the stated equality generalises to open manifolds a result by Varopoulos. 0. Introduction.
SPECTRAL DISTRIBUTION AND L 2ISOPERIMETRIC PROFILE OF LAPLACE OPERATORS ON GROUPS
, 901
"... Abstract. We give a formula relating the L 2isoperimetric profile to the spectral distribution of the Laplace operator associated to a finitely generated group Γ or a Riemannian manifold with a cocompact, isometric Γaction. As a consequence, we can apply techniques from geometric group theory to e ..."
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Cited by 1 (1 self)
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Abstract. We give a formula relating the L 2isoperimetric profile to the spectral distribution of the Laplace operator associated to a finitely generated group Γ or a Riemannian manifold with a cocompact, isometric Γaction. As a consequence, we can apply techniques from geometric group theory to estimate the spectral distribution of the Laplace operator in terms of the growth and the Følner’s function of the group, generalizing previous estimates by Gromov and Shubin. This leads, in particular, to sharp estimates of the spectral distributions for several classes of solvable groups. Furthermore, we prove the asymptotic invariance of the spectral distribution under changes of measures with finite second moment. 1.
unknown title
, 2009
"... Isoperimetric profile of subgroups and probability of return of random walks on elementary solvable groups ∗ ..."
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Isoperimetric profile of subgroups and probability of return of random walks on elementary solvable groups ∗
Asymptotic dimension and NovikovShubin invariants for Open Manifolds
, 1996
"... A trace on the C ∗algebra A of quasilocal operators on an open manifold is described, based on the results in [36]. It allows a description à la NovikovShubin [31] of the low frequency behavior of the LaplaceBeltrami operator. The 0th NovikovShubin invariant defined in terms of such a trace is ..."
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A trace on the C ∗algebra A of quasilocal operators on an open manifold is described, based on the results in [36]. It allows a description à la NovikovShubin [31] of the low frequency behavior of the LaplaceBeltrami operator. The 0th NovikovShubin invariant defined in terms of such a trace is proved to coincide with a metric invariant, which we call asymptotic dimension, thus giving a large scale “Weyl asymptotics ” relation. Moreover, in analogy with the ConnesWodzicki result [7, 8, 45], the asymptotic dimension d measures the singular traceability (at 0) of the LaplaceBeltrami operator, namely we may construct a (type II1) singular trace which is finite on the ∗bimodule over A generated by ∆ −d/2. 1 Asymptotic dimension and NovikovShubin invariants 2 0 Introduction. The inspiration of this paper came from the idea of Connes ’ [8] of defining the dimension of a noncommutative compact manifold in terms of the Weyl asymptotics,
A WEYL TYPE FORMULA RELATING SPECTRAL DISTRIBUTION TO L 2ISOPERIMETRIC PROFILE
, 901
"... Abstract. We give a formula relating the L 2isoperimetric profile to the spectral distribution of the Laplace operator associated to a finitely generated group Γ or a Riemannian manifold with a cocompact, isometric Γaction. As a consequence, we can apply techniques from geometric group theory to e ..."
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Abstract. We give a formula relating the L 2isoperimetric profile to the spectral distribution of the Laplace operator associated to a finitely generated group Γ or a Riemannian manifold with a cocompact, isometric Γaction. As a consequence, we can apply techniques from geometric group theory to estimate the spectral distribution of the Laplace operator in terms of the growth and the Følner’s function of the group, generalizing previous estimates by Gromov and Shubin. This leads, in particular, to sharp estimates of the spectral distributions for several classes of solvable groups. Furthermore, we prove the asymptotic invariance of the spectral distribution under changes of measures with finite second moment. 1.