- Research Article
25
- 10.1016/j.ic.2011.02.003
Unprovability of the logical characterization of bisimulation
- Apr 07, 2011
- Information and Computation
- Pedro Sánchez Terraf
Unprovability of the logical characterization of bisimulation
We study an integration theory on general measure spaces without imposing the convention infinity times zero equals zero. Our approach depends upon the premises concerning the countable additivity of the corresponding measure and the fact that the measure of the empty set is zero. An outstanding feature of this approach concerns the fact that all the results obtained in this paper are implied by the Third Littlewood’s principle and a Fundamental Theorem asserting that if a bounded real-valued function defined on a set of finite measure is measurable then it is integrable.
Unprovability of the logical characterization of bisimulation
Unprovability of the logical characterization of bisimulation
On-diagonal Heat Kernel Lower Bound for Strongly Local Symmetric Dirichlet Forms
This paper studies strongly local symmetric Dirichlet forms on general measure spaces. The underlying space is equipped with the intrinsic metric induced by the Dirichlet form, with respect to which the metric measure space does not necessarily satisfy volume-doubling property. Assuming Nash-type inequality, it is proved in this paper that outside a properly exceptional set, if a pointwise on-diagonal heat kernel upper bound in terms of the volume function is known a priori, then the comparable heat kernel lower bound also holds. The only assumption made on the volume growth rate is that it can be bounded by a continuous function satisfying doubling property, in other words, is not exponential.
Read moreSome new results on transition probability
In this paper, we study the basic properties of stationary transition probability of Markov processes on a general measurable space (E, ℰ), such as the continuity, maximum probability, zero point, positive probability set,standardization, and obtain a series of important results such as Continuity Theorem, Representation Theorem, Levy Theorem and so on. These results are very useful for us to study stationary tri-point transition probability on a general measurable space (E, ℰ). Our main tools such as Egoroff’s Theorem, Vitali-Hahn-Saks’s Theorem and the theory of atomic set and well-posedness of measure are also very interesting and fashionable.
Read moreA remark on a lemma from Filippov’s article on diff tial inclusions
The Filippov’s article discusses a possible definition of the solution of differential equation with discontinuous right-hand side. The lemma on the structure of the set defining differential inclusion given by Filippov implies an equivalent solution definition, which allows us to expand possible domains and codomains of the function, that is in the right-hand side of the equation. In this paper we find a generalization of this lemma to the case of general topologic and measure spaces. Proofs of corresponding theorems are given here.
Read moreIsomorphic classification of Lp,q-spaces, II
Isomorphic classification of Lp,q-spaces, II
Differential structure associated to axiomatic Sobolev spaces
Differential structure associated to axiomatic Sobolev spaces
Perimeter as relaxed Minkowski content in metric measure spaces
Perimeter as relaxed Minkowski content in metric measure spaces
Integration theory
Having made acquaintance in the last chapter with the fundamentals of measure theory, we will now turn to the theory of integration. In the first part of the chapter we study integrals over general measure spaces, while in the second half we take advantage of the special properties of the Lebesgue measure.
Read moreOn ergodic measure-preserving transformations defined on an infinite measure space
Few, if any, of the properties enjoyed by ergodic measure-preserving transformations defined on a finite measure space generalize in a natural way to those defined on an infinite measure space. Concrete examples of ergodic transformations which preserve a finite measure and ones which preserve an infinite measure exist in the literature, see [1]. It is not difficult to see that ergodic transformations never admit wandering sets of positive measure. In [2 ] it was shown that a basic difference exists between ergodic transformations which preserve a finite measure and those which preserve an infinite measure; namely, an ergodic measure-preserving transformation defined on an infinite measure space always admits weakly wandering sets of positive measure (Theorem 2 of [2]). Unlike wandering sets, it is not true in general that the union of two weakly wandering sets is again a weakly wandering set even if we require that a class of mutually disjoint images of one weakly wandering set does not intersect a class of mutually disjoint images of the other. One may ask then if there are any ergodic measure-preserving transformations defined on an infinite measure space which admit only weakly wandering sets of finite measure. In this paper we show that this is not the case. We prove that there always exist weakly wandering sets of infinite measure for any ergodic measure-preserving transformation defined on an infinite measure space (Theorem 3). In [2] the existence of a weakly wandering set of positive measure for an ergodic measure-preserving transformation defined on an infinite measure space was discovered while studying the necessary and sufficient conditions for the existence of a finite, invariant, and equivalent measure for a given measurable and nonsingular transformation. In this paper we construct the weakly wandering sets in a different way. Using the pointwise ergodic theorem we prove a simple and yet a useful fact about ergodic measure-preserving transformations defined on an infinite measure space (Theorem 2). It states that given two sets A and B both of finite measure, it is possible to find an image of A under some power of the transformation T which has small intersection with the set B. This fact is basic in proving Lemma 1 which shows the existence of a
Read moreBipartite Rokhsar–Kivelson points and Cantor deconfinement
Quantum dimer models on bipartite lattices exhibit Rokhsar--Kivelson points with exactly known critical ground states and deconfined spinons. We examine generic, weak perturbations around these points. In $d=2+1$ we find a first-order transition between a ``plaquette'' valence bond crystal and a region with a devil's staircase of commensurate and incommensurate valence bond crystals. In the part of the phase diagram where the staircase is incomplete, the incommensurate states exhibit a gapless photon and deconfined spinons on a set of finite measure, almost but not quite a deconfined phase in a compact $U(1)$ gauge theory in $d=2+1$! In $d=3+1$, we find a continuous transition between the $U(1)$ resonating valence bond phase and a deconfined staggered valence bond crystal. In an appendix, we comment on analogous phenomena in quantum vertex models, most notably the existence of a continuous transition on the triangular lattice in $d=2+1$.
Read moreProof of a conjecture on the supports of Wigner distributions
In this note we prove that the Wigner distribution of an f ∈ L2(ℝn) cannot be supported by a set of finite measure in ℝ2n unless f=0. We prove a corresponding statement for cross-ambiguity functions. As a strengthening of the conjecture we show that for an f ∈ L2(ℝn) its Wigner distribution has a support of measure 0 or ∞ in any half-space of ℝ2n.
Read moreNew results on the continuous Weinstein wavelet transform
We consider the continuous wavelet transform mathcal{S}_{h}^{W} associated with the Weinstein operator. We introduce the notion of localization operators for mathcal {S}_{h}^{W}. In particular, we prove the boundedness and compactness of localization operators associated with the continuous wavelet transform. Next, we analyze the concentration of mathcal{S}_{h}^{W} on sets of finite measure. In particular, Benedicks-type and Donoho-Stark’s uncertainty principles are given. Finally, we prove many versions of Heisenberg-type uncertainty principles for mathcal{S}_{h}^{W}.
Read moreA synthetic approach to Markov kernels, conditional independence and theorems on sufficient statistics
We develop Markov categories as a framework for synthetic probability and statistics, following work of Golubtsov as well as Cho and Jacobs. This means that we treat the following concepts in purely abstract categorical terms: conditioning and disintegration; various versions of conditional independence and its standard properties; conditional products; almost surely; sufficient statistics; versions of theorems on sufficient statistics due to Fisher–Neyman, Basu, and Bahadur.Besides the conceptual clarity offered by our categorical setup, its main advantage is that it provides a uniform treatment of various types of probability theory, including discrete probability theory, measure-theoretic probability with general measurable spaces, Gaussian probability, stochastic processes of either of these kinds, and many others.
Read moreDempster Combination Rule for Signed Belief Functions
A possibility to define a binary operation over the space of pairs of belief functions, inverse or dual to the well-known Dempster combination rule in the same sense in which substraction is dual with respect to the addition operation in the space of real numbers, can be taken as an important problem for the purely algebraic as well as from the application point of view. Or, it offers a way how to eliminate the modification of a belief function obtained when combining this original belief function with other pieces of information, later proved not to be reliable. In the space of classical belief functions definable by set-valued (generalized) random variables defined on a probability space, the invertibility problem for belief functions, resulting from the above mentioned problem of "dual" combination rule, can be proved to be unsolvable up to trivial cases. However, when generalizing the notion of belief functions in such a way that probability space is replaced by more general measurable space with signed measure, inverse belief functions can be defined for a large class of belief functions generalized in the corresponding way. "Dual" combination rule is then defined by the application of the Dempster rule to the inverse belief functions.
Read moreInequivalent measures of noncompactness
Two homogeneous measures of noncompactness β and γ on an infinite dimensional Banach space X are called “equivalent” if there exist positive constants b and c such that bβ(S) ≤ γ(S) ≤ cβ(S) for all bounded sets \({S\subset X}\). If such constants do not exist, the measures of noncompactness are “inequivalent.” We ask a foundational question which apparently has not previously been considered: For what infinite dimensional Banach spaces do there exist inequivalent measures of noncompactness on X? We provide here the first examples of inequivalent measures of noncompactness. We prove that such inequivalent measures exist if X is a Hilbert space; or if (Ω, Σ, μ) is a general measure space, 1 ≤ p ≤ ∞, and X = Lp(Ω, Σ, μ); or if K is a compact Hausdorff space and X = C(K); or if K is a compact metric space, 0 < λ ≤ 1, and X = C0,λ(K), the Banach space of Holder continuous functions with Holder exponent λ. We also prove the existence of such inequivalent measures of noncompactness if Ω is an open subset of \({\mathbb{R}^n}\) and X is the Sobolev space Wm,p(Ω). Our motivation comes from questions about existence of eigenvectors of homogeneous, continuous, order-preserving cone maps f : C→C and from the closely related issue of giving the proper definition of the “cone essential spectral radius” of such maps. These questions are considered in the companion paper [28]; see, also, [27].
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