Results 31 to 40 of about 4,038,548 (77)

On an Erdős similarity problem in the large

open access: yesBulletin of the London Mathematical Society, Volume 57, Issue 6, Page 1801-1818, June 2025.
Abstract In a recent paper, Kolountzakis and Papageorgiou ask if for every ε∈(0,1]$\epsilon \in (0,1]$, there exists a set S⊆R$S \subseteq \mathbb {R}$ such that |S∩I|⩾1−ε$\vert S \cap I\vert \geqslant 1 - \epsilon$ for every interval I⊂R$I \subset \mathbb {R}$ with unit length, but that does not contain any affine copy of a given increasing sequence ...
Xiang Gao   +2 more
wiley   +1 more source

ℓp$\ell ^p$ metrics on cell complexes

open access: yesJournal of the London Mathematical Society, Volume 111, Issue 1, January 2025.
Abstract Motivated by the observation that groups can be effectively studied using metric spaces modelled on ℓ1$\ell ^1$, ℓ2$\ell ^2$ and ℓ∞$\ell ^\infty$ geometry, we consider cell complexes equipped with an ℓp$\ell ^p$ metric for arbitrary p$p$. Under weak conditions that can be checked locally, we establish non‐positive curvature properties of these
Thomas Haettel, Nima Hoda, Harry Petyt
wiley   +1 more source

Error estimates for completely discrete FEM in energy‐type and weaker norms

open access: yesNumerical Methods for Partial Differential Equations, Volume 40, Issue 6, November 2024.
Abstract The paper presents error estimates within a unified abstract framework for the analysis of FEM for boundary value problems with linear diffusion‐convection‐reaction equations and boundary conditions of mixed type. Since neither conformity nor consistency properties are assumed, the method is called completely discrete.
Lutz Angermann   +2 more
wiley   +1 more source

Determining a time‐varying potential in time‐fractional diffusion from observation at a single point

open access: yesNumerical Methods for Partial Differential Equations, Volume 40, Issue 6, November 2024.
Abstract We discuss the identification of a time‐dependent potential in a time‐fractional diffusion model from a boundary measurement taken at a single point. Theoretically, we establish a conditional Lipschitz stability for this inverse problem. Numerically, we develop an easily implementable iterative algorithm to recover the unknown coefficient, and
Siyu Cen, Kwancheol Shin, Zhi Zhou
wiley   +1 more source

Cyclic‐Schottky strata of Schottky space

open access: yesBulletin of the London Mathematical Society, Volume 56, Issue 11, Page 3412-3427, November 2024.
Abstract Schottky space Sg${\mathcal {S}}_{g}$, where g⩾2$g \geqslant 2$ is an integer, is a connected complex orbifold of dimension 3(g−1)$3(g-1)$; it provides a parametrization of the PSL2(C)${\rm PSL}_{2}({\mathbb {C}})$‐conjugacy classes of Schottky groups Γ$\Gamma$ of rank g$g$. The branch locus Bg⊂Sg${\mathcal {B}}_{g} \subset {\mathcal {S}}_{g}$,
Rubén A. Hidalgo, Milagros Izquierdo
wiley   +1 more source

Optimal control of stochastic partial differential equations in Banach spaces [PDF]

open access: yes, 2010
In this thesis we study optimal control problems in Banach spaces for stochastic partial differential equations. We investigate two different approaches.
Serrano Perdomo, Rafael Antonio
core   +5 more sources

Assumed strain methods in micromechanics, laminate composite voxels and level sets

open access: yesInternational Journal for Numerical Methods in Engineering, Volume 125, Issue 11, 15 June 2024.
Abstract This work deals with the composite voxel method, which—in its original form—furnishes voxels containing more than one material with a surrogate material law accounting for the heterogeneity in the voxel. We show that the laminate composite voxel technique naturally arises as an assumed strain method, that is, the general framework introduced ...
Jonas Lendvai, Matti Schneider
wiley   +1 more source

Compact convex sets free of inner points in infinite‐dimensional topological vector spaces

open access: yesMathematische Nachrichten, Volume 297, Issue 5, Page 1668-1677, May 2024.
Abstract An inner point of a non‐singleton convex set M$M$ is a point x∈M$x\in M$ satisfying that for all m∈M∖{x}$m\in M\setminus \lbrace x\rbrace$ there exists n∈M∖{m,x}$n\in M\setminus \lbrace m,x\rbrace$ such that x∈(m,n)$x\in (m,n)$. We prove the existence of convex compact subsets free of inner points in the infinite‐dimensional setting. Following
Almudena Campos‐Jiménez   +1 more
wiley   +1 more source

Delta‐points and their implications for the geometry of Banach spaces

open access: yesJournal of the London Mathematical Society, Volume 109, Issue 5, May 2024.
Abstract We show that the Lipschitz‐free space with the Radon–Nikodým property and a Daugavet point recently constructed by Veeorg is in fact a dual space isomorphic to ℓ1$\ell _1$. Furthermore, we answer an open problem from the literature by showing that there exists a superreflexive space, in the form of a renorming of ℓ2$\ell _2$, with a Δ$\Delta ...
Trond A. Abrahamsen   +6 more
wiley   +1 more source

A subsequence characterization of sequences spanning isomorphically polyhedral Banach spaces [PDF]

open access: yes, 1998
Let (x_n) be a sequence in a Banach space X which does not converge in norm, and let E be an isomorphically precisely norming set for X such that (*) ∑_n |x*(x_{n+1} - x_n)| < ∞, ∀x* ∈ E.
Androulakis, G.
core  

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