Results 11 to 20 of about 339,707 (116)
A new proof of Lusin's theorem [PDF]
Fundamenta Mathematicae, 1927 The purpose of this paper is to give a new proof of the following Lusin's theorem: Théorème: If f(x) is a measurable function defined on the interval I: 0 ≤ x ≤ 1, then for every ϵ > 0 there is a set A ⊂ I such that f(x) is continuous on A and m(I-A ...
Cohen, Leon
openaire +3 more sources
On a geometric combination of functions related to Prékopa–Leindler inequality
Mathematika, Volume 69, Issue 2, Page 482-507, April 2023., 2023 Abstract We introduce a new operation between nonnegative integrable functions on Rn$\mathbb {R}^n$, that we call geometric combination; it is obtained via a mass transportation approach, playing with inverse distribution functions. The main feature of this operation is that the Lebesgue integral of the geometric combination equals the geometric mean ...
Graziano Crasta, Ilaria Fragalà
wiley +1 more source
Journal of Function Spaces, Volume 2023, Issue 1, 2023., 2023 Let L = −Δ + V be a Schrödinger operator on ℝn, where Δ denotes the Laplace operator ∑i=1n∂2/∂xi2 and V is a nonnegative potential belonging to a certain reverse Hölder class RHq(ℝn) with q > n/2. In this paper, by the regularity estimate of the fractional heat kernel related with L, we establish the quantitative weighted boundedness of Littlewood ...
Li Yang, Pengtao Li, Andrea Scapellato
wiley +1 more source
Two‐dimensional metric spheres from gluing hemispheres
Journal of the London Mathematical Society, Volume 106, Issue 4, Page 3069-3102, December 2022., 2022 Abstract We study metric spheres (Z,dZ)$(Z, d_{Z} )$ obtained by gluing two hemispheres of S2$\mathbb {S}^{2}$ along an orientation‐preserving homeomorphism g:S1→S1$g \colon \mathbb {S}^{1} \rightarrow \mathbb {S}^{1}$, where dZ$d_{Z}$ is the canonical distance that is locally isometric to S2$\mathbb {S}^{2}$ off the seam. We show that if (Z,dZ)$(Z, d_{
Toni Ikonen
wiley +1 more source
Journal of Function Spaces, Volume 2022, Issue 1, 2022., 2022 Let (X, d, μ) be a metric measure space endowed with a metric d and a non‐negative Borel doubling measure μ. Let L be a non‐negative self‐adjoint operator on L2(X). Assume that the (heat) kernel associated to the semigroup e−tL satisfies a Gaussian upper bound.
Jiawei Shen +3 more
wiley +1 more source
Comparison theorem of one-dimensional stochastic hybrid delay systems [PDF]
, 2008 The comparison theorem of stochastic differential equations has been investigated by many authors. However, little research is available on the comparison theorem of stochastic hybrid systems, which is the topic of this paper.
Yuan, Chenggui +6 more
core +4 more sources
Haar null and Haar meager sets: a survey and new results
Bulletin of the London Mathematical Society, Volume 52, Issue 4, Page 561-619, August 2020., 2020 Abstract We survey results about Haar null subsets of (not necessarily locally compact) Polish groups. The aim of this paper is to collect the fundamental properties of the various possible definitions of Haar null sets, and also to review the techniques that may enable the reader to prove results in this area.
Márton Elekes, Donát Nagy
wiley +1 more source
Lusin-type theorem for functions with prescribed gradient [PDF]
In the first part of this thesis we discuss and prove a theorem by Giovanni Alberti whose statement shares similarities to that of Lusin's Theorem, hence the "Lusin-type theorem" definition. The theorem states that given a Borel vector field f on a finite measure set and some epsilon greater than zero, it is always possible to find a set of measure ...
PRATI, EMANUELE
openaire +2 more sources
Dynamic games with (almost) perfect information
Theoretical Economics, Volume 15, Issue 2, Page 811-859, May 2020., 2020 This paper aims to solve two fundamental problems on finite‐ or infinite‐horizon dynamic games with complete information. Under some mild conditions, we prove the existence of subgame‐perfect equilibria and the upper hemicontinuity of equilibrium payoffs in general dynamic games with simultaneous moves (i.e., almost perfect information), which go ...
Wei He, Yeneng Sun
wiley +1 more source
Egoroff’s Theorem and Lusin’s Theorem for Capacities in the Framework of g‐Expectation
Mathematical Problems in Engineering, Volume 2020, Issue 1, 2020., 2020 In the classical real analysis theory, Egoroff’s theorem and Lusin’s theorem are two of the most important theorems. The σ‐additivity of measures plays a crucial role in the proofs of these theorems. Later, many researchers have carried out lots of studies on Egoroff’s theorem and Lusin’s theorem when the measure is monotone and nonadditive (see, e.g.,
Zhaojun Zong +3 more
wiley +1 more source