Results 21 to 30 of about 96 (68)

Uniformly Normal Structure of Orlicz Function Spaces Equipped with the p-Amemiya Norm

Journal of Harbin University of Science and Technology
In this paper, we mainly investigate the uniformly normal structure of Orlicz function spaces equipped with the p-Amemiya norm. A necessary and sufficient condition for Orlicz function spaces equipped with the p-Amemiya norm to have a uniformly normal
ZUO Mingxia, XU Zeyu
doaj   +1 more source

Empirical‐Process Limit Theory and Filter Approximation Bounds for Score‐Driven Time Series Models

Journal of Time Series Analysis, EarlyView.
ABSTRACT This article examines the filtering and approximation‐theoretic properties of score‐driven time series models. Under specific Lipschitz‐type and tail conditions, new results are derived, leading to maximal and deviation inequalities for the filtering approximation error using empirical process theory.
Enzo D'Innocenzo
wiley   +1 more source

Risk Measure Duality Without Structure

Mathematical Finance, EarlyView.
ABSTRACT We study risk measures on vector spaces of random variables which a priori have little structure, such as spaces lacking law invariance or a lattice structure. Ensuring the existence of a tractable dual representation (one which does not contain non‐sigma‐additive measures) is one of the main problems in risk measure theory, and we address it ...
Vasily Melnikov
wiley   +1 more source

Large Covariance Matrix Estimation by Penalized Log‐Det Heuristics

Statistical Analysis and Data Mining: An ASA Data Science Journal, Volume 19, Issue 5, October 2026.
ABSTRACT We study covariance estimation in high‐dimensional approximate factor models with a sparse residual covariance. The estimator combines a log‐det loss with nuclear‐norm and off‐diagonal ℓ1$$ {\mathrm{\ell}}_1 $$ penalties on a sample‐normalized covariance scale.
Enrico Bernardi, Matteo Farnè
wiley   +1 more source

Amenability Constants for Unconditional Sums of Banach Algebras

Mathematische Nachrichten, Volume 299, Issue 9, Page 2472-2494, September 2026.
ABSTRACT We study Johnson amenability for unconditional direct sums of Banach algebras. Given a family (Ai)i∈I$(A_i)_{i\in I}$ of Banach algebras and a Banach sequence lattice E$E$ on I$I$, the E$E$‐sum ⨁i∈IAiE${\bigl (\bigoplus _{i\in I} A_i\bigr)}_{\!E}$ carries a natural Banach algebra structure via coordinatewise multiplication.
Tomasz Kania, Jerzy Ka̧kol
wiley   +1 more source

Smooth Points of Orlicz Function Spaces Equipped with S-norm

Journal of Harbin University of Science and Technology
Smooth points are important concepts in Banach space geometry theory, which have important applications in estimation theory, probability theory and other fields.
XU Hao, WANG Junming
doaj   +1 more source

Uniform rotundity in every direction of Orlicz-Sobolev spaces

Journal of Inequalities and Applications, 2016
In this paper, we study the extreme points and rotundity of Orlicz-Sobolev spaces. Analyzing and combining the properties of both Orlicz spaces and Sobolev spaces, we get the sufficient and necessary criteria for Orlicz-Sobolev spaces equipped with a ...
Fayun Cao, Rui Mao, Bing Wang
doaj   +1 more source

Well‐posedness of heat equations with nonlinearities of arbitrarily rapid growth

Proceedings of the London Mathematical Society, Volume 133, Issue 3, September 2026.
Abstract We address local‐ and global‐in‐time well‐posedness of the Cauchy problem for nonlinear heat equations without imposing growth rate restrictions on the nonlinearity a priori. Our results constitute a nontrivial expansion of the classical Lq$L^q$‐theory for nonlinearities dominated by polynomial growth and the exponential‐Orlicz space theory ...
Yohei Fujishima, Kotaro Hisa, Robert Laister   +2 more
wiley   +1 more source

Existence of Solution for Two Classes of Quasilinear Systems Defined on a Nonreflexive Orlicz–Sobolev Spaces

Mathematical Methods in the Applied Sciences, Volume 49, Issue 12, Page 13324-13360, August 2026.
ABSTRACT This paper proves the existence of nontrivial solution for two classes of quasilinear systems of the type −ΔΦ1u=Fu(x,u,v)+λRu(x,u,v)inΩ−ΔΦ2v=−Fv(x,u,v)−λRv(x,u,v)inΩu=v=0on∂Ω$$ \left\{\begin{array}{l}\hfill -{\Delta}_{\Phi_1}u={F}_u\left(x,u,v\right)+\lambda {R}_u\left(x,u,v\right)\kern0.1832424242424242em \mathrm{in}\kern0.3em \Omega ...
Lucas da Silva, Marco Souto
wiley   +1 more source

Self‐improving property for certain degenerate functionals with generalized Orlicz growth

Bulletin of the London Mathematical Society, Volume 58, Issue 8, August 2026.
Abstract We investigate a self‐improving property of variational integrals in a weighted framework under generalized Orlicz growth conditions. Assuming that the weight belongs to an appropriate Muckenhoupt class and the growth function satisfies standard structural conditions, we prove that the gradient of any local quasi‐minimizer has local higher ...
Vertti Hietanen, Mikyoung Lee
wiley   +1 more source