Results 21 to 30 of about 152,964,033 (109)

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

On the Existence of Solutions of Dynamic Equations on Time Scales in Banach Spaces

Mathematical Methods in the Applied Sciences, Volume 49, Issue 13, Page 15358-15384, 15 September 2026.
ABSTRACT In this paper we address the question of solvability of dynamic equations on time scales in Banach spaces. In particular, our main theorem extends the result for classical differential equations in Banach spaces of Banaś and Goebel established in [5], to an arbitrary time scale.
Dušan Oberta
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

Rothe Time Discretization and Weak Solutions for a Cutoff Westervelt System

Numerical Methods for Partial Differential Equations, Volume 42, Issue 5, September 2026.
ABSTRACTWe study a fully implicit Rothe time discretization for a cutoff first‐order formulation of the Westervelt equation. The key ingredients are the enthalpy variable and the primitive mobility variable, which turn each nonlinear time step into a uniformly monotone elliptic problem and avoid higher‐order energy estimates and inverse inequalities ...
Marvin Fritz
wiley   +1 more source

On the chain of commuting operators on Banach spaces

Bulletin of the London Mathematical Society, Volume 58, Issue 9, September 2026.
Abstract An operator T$T$ on a Banach space is said to be of chain N$N$ if there exist non‐scalar operators S1,⋯,SN−1$S_1,\dots,S_{N-1}$ and a non‐zero compact operator K$K$ such that T↔S1↔S2↔⋯↔SN−1↔K,$$\begin{equation*} T \leftrightarrow S_1 \leftrightarrow S_2 \leftrightarrow \dots \leftrightarrow S_{N-1} \leftrightarrow K, \end{equation*}$$where A↔B$
Tomasz Szczepanski
wiley   +1 more source

When weak convergence in von Neumann algebras implies almost uniform convergence?

Bulletin of the London Mathematical Society, Volume 58, Issue 9, September 2026.
Abstract We show that weak sequential convergence in a semifinite von Neumann algebra M$\mathcal {M}$ equipped with a faithful normal semifinite trace τ$\tau$ implies almost uniform convergence if and only if M$\mathcal {M}$ is of type Ifin$\mathrm{I}_{\rm fin}$ with τ(1)<∞;$\tau (\mathbf {1})<\infty;$ and that weak sequential convergence in a finite ...
Yerlan Nessipbayev, Fedor Sukochev, Dmitriy Zanin   +2 more
wiley   +1 more source

Equidistribution in 2‐nilpotent Polish groups and triple restricted sumsets

Journal of the London Mathematical Society, Volume 114, Issue 3, September 2026.
Abstract The aim of this paper is to establish a Ratner‐type equidistribution theorem for orbits on homogeneous spaces associated with 2$\hskip.001pt 2$‐nilpotent locally compact Polish groups under the action of a countable discrete abelian group.
Ethan Ackelsberg, Asgar Jamneshan
wiley   +1 more source

A new approach for the analysis of evolution partial differential equations on a finite interval

Journal of the London Mathematical Society, Volume 114, Issue 3, September 2026.
Abstract We show that, for certain evolution partial differential equations, the solution on a finite interval (0,ℓ)$(0,\ell)$ can be reconstructed as a superposition of restrictions to (0,ℓ)$(0,\ell)$ of solutions to two associated partial differential equations posed on the half‐lines (0,∞)$(0,\infty)$ and (−∞,ℓ)$(-\infty,\ell)$.
Türker Özsarı, Dionyssios Mantzavinos, Konstantinos Kalimeris   +2 more
wiley   +1 more source

Self‐Similar Blowup for the Cubic Schrödinger Equation

Communications on Pure and Applied Mathematics, Volume 79, Issue 8, Page 1831-1918, August 2026.
ABSTRACT We give a rigorous proof for the existence of a finite‐energy, self‐similar solution to the focusing cubic Schrödinger equation in three spatial dimensions. The proof is computer‐assisted and relies on a fixed point argument that shows the existence of a solution in the vicinity of a numerically constructed approximation.
Roland Donninger, Birgit Schörkhuber
wiley   +1 more source

Invariant Measure and Universality of the 2D Yang–Mills Langevin Dynamic

Communications on Pure and Applied Mathematics, Volume 79, Issue 8, Page 1973-2102, August 2026.
ABSTRACT We prove that the Yang–Mills (YM) measure for the trivial principal bundle over the two‐dimensional torus, with any connected, compact structure group, is invariant for the associated renormalised Langevin dynamic. Our argument relies on a combination of regularity structures, lattice gauge‐fixing and Bourgain's method for invariant measures ...
Ilya Chevyrev, Hao Shen
wiley   +1 more source