Results 61 to 70 of about 8,714,469 (204)

Banach spaces of functions analytic in a polydisc

International Journal of Mathematics and Mathematical Sciences, 1986
This paper is concerned with functions of several complex variables analytic in the unit polydisc. Certain Banach spaces to which these functions might belong are defined and some relationships between them are developed.
Leon M. Hall
doaj   +1 more source

On shrinking projection method for cutter type mappings with nonsummable errors

Journal of Inequalities and Applications, 2023
We prove two key inequalities for metric and generalized projections in a certain Banach space. We then obtain some asymptotic behavior of a sequence generated by the shrinking projection method introduced by Takahashi et al. (J. Math. Anal. Appl.
Takanori Ibaraki, Satit Saejung
doaj   +1 more source

The Optimal Mean–Variance Selling Problem With Finite Horizon

Mathematical Finance, EarlyView.
ABSTRACT The optimal mean–variance selling problem seeks to determine a dynamically optimal stopping time in the nonlinear problem sup0≤τ≤TE(Xτ)−cVar(Xτ)$\sup _{0 \le \tau \le T} \left[ \mathsf {E}\,\!(X_\tau) - c\, \mathsf {V}ar\,\!(X_\tau) \right]$, where X$X$ is a geometric Brownian motion with strictly positive drift, the supremum is taken over ...
Peter Johnson, Jesper Lund Pedersen, Goran Peskir   +2 more
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

Inverse problems for semilinear elliptic PDE with a general nonlinearity a(x,u)$a(x,u)$

Transactions of the London Mathematical Society, Volume 13, Issue 1, December 2026.
Abstract This article studies the inverse problem of recovering a nonlinearity in an elliptic equation Δu+a(x,u)=0$\Delta u + a(x,u) = 0$ from boundary measurements of solutions. Previous results based on first‐order linearization achieve this under a sign condition on ∂ua(x,u)$\partial _u a(x,u)$, and results based on higher order linearization ...
David Johansson, Janne Nurminen, Mikko Salo   +2 more
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

Generalizations of the Lax-Milgram Theorem

Boundary Value Problems, 2007
We prove a linear and a nonlinear generalization of the Lax-Milgram theorem. In particular, we give sufficient conditions for a real-valued function defined on the product of a reflexive Banach space and a normed space to represent all bounded linear ...
Dimosthenis Drivaliaris, Nikos Yannakakis   +1 more
doaj   +2 more sources

ON THE ALMOST PERIODIC AT INFINITY FUNCTIONS FROM HOMOGENEOUS SPACES

Проблемы анализа, 2018
We consider homogeneous spaces of functions defined on the real axis (or semi-axis) with values in a complex Banach space. We study the new class of almost periodic at infinity functions from homogeneous spaces.
Baskakov A. G., Strukov V. E., Strukova I. I.   +2 more
doaj   +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