Results 51 to 60 of about 11,694 (136)

Existence of Weak Solutions for a Degenerate Goursat‐Type Linear Problem

Mathematical Methods in the Applied Sciences, Volume 48, Issue 15, Page 14334-14341, October 2025.
ABSTRACT For a generalization of the Gellerstedt operator with mixed‐type Dirichlet boundary conditions to a suitable Tricomi domain, we prove the existence and uniqueness of weak solutions of the linear problem and for a generalization of this problem.
Olimpio Hiroshi Miyagaki, Carlos Alberto Reyes Peña, Rodrigo da Silva Rodrigues   +2 more
wiley   +1 more source

A structural version of the theorem of Hahn-Banach [PDF]

, 2001
We consider one of the basic results of functional analysis, the classical theorem of Hahn-Banach. This theorem gives the existence of a continuous linear functional on a given normed vectorspace extending a given continuous linear functional on a ...
Brinkhuis, J. (Jan)
core  

Factorizations and minimality of the Calkin Algebra norm for C(K)$C(K)$‐spaces

Journal of the London Mathematical Society, Volume 112, Issue 4, October 2025.
Abstract For a scattered, locally compact Hausdorff space K$K$, we prove that the essential norm on the Calkin algebra B(C0(K))/K(C0(K))$\mathcal {B}(C_0(K))/\mathcal {K}(C_0(K))$ is a minimal algebra norm. The proof relies on establishing a quantitative factorization for the identity operator on c0$c_0$ through noncompact operators T:C0(K)→X$T: C_0(K)
Antonio Acuaviva
wiley   +1 more source

Uniform approximation of continuous functions by smooth functions with no critical points on Hilbert manifolds [PDF]

, 2001
We prove that every continuous function on a separable infinite-dimensional Hilbert space X can be uniformly approximated by smooth functions with no critical points. This kind of result can be regarded as a sort of very strong approximate version of the
Azagra, Daniel, Boiso, Manuel Cepedello
core   +1 more source

Peer Effects in Binary Outcomes: Strategic Complementarity and Taste for Conformity With Endogenous Networks

Journal of Applied Econometrics, Volume 40, Issue 6, Page 608-626, September/October 2025.
ABSTRACT This paper introduces a generalized model of peer effects for binary outcomes, based on a network game that accounts for strategic complementarity (influence of the number of peers that select the same action) and conformity to social norms (penalizing deviations from the average peers' action).
Mathieu Lambotte
wiley   +1 more source

Traces on the uniform tracial completion of Z$\mathcal {Z}$‐stable C∗${\rm C}^*$‐algebras

Journal of the London Mathematical Society, Volume 111, Issue 6, June 2025.
Abstract The uniform tracial completion of a C∗${\rm C}^*$‐algebra A$A$ with compact trace space T(A)≠∅$T(A) \ne \emptyset$ is obtained by completing the unit ball with respect to the uniform 2‐seminorm ∥a∥2,T(A)=supτ∈T(A)τ(a∗a)1/2$\Vert a\Vert _{2,T(A)}=\sup _{\tau \in T(A)} \tau (a^*a)^{1/2}$. The trace problem asks whether every trace on the uniform
Samuel Evington
wiley   +1 more source

The Granger–Johansen representation theorem for integrated time series on Banach space

Journal of Time Series Analysis, Volume 46, Issue 3, Page 432-457, May 2025.
We prove an extended Granger–Johansen representation theorem (GJRT) for finite‐ or infinite‐order integrated autoregressive time series on Banach space. We assume only that the resolvent of the autoregressive polynomial for the series is analytic on and inside the unit circle except for an isolated singularity at unity.
Phil Howlett, Brendan K. Beare, Massimo Franchi, John Boland, Konstantin Avrachenkov   +4 more
wiley   +1 more source

Hahn-Banach Theorem in Vector Spaces

Journal of Mathematical Extension, 2010
. In this paper we introduce a new extension to Hahn-Banach Theorem and consider its relation with the linear operatres.
M. R. Haddad, H. Mazaheri
doaj  

Analytical method for solving linear abstract differential equations of order n

Partial Differential Equations in Applied Mathematics
In this paper, the concept of point-wise independent set of closed operators is introduced. The new concept together with the use of Hahn–Banach Theorem enable us to reduce an inhomogeneous linear abstract differential equation of order n namely, Anu(n ...
Waseem Ghazi Alshanti, Ma’mon Abu Hammad, Ahmad Alshanty, Roshdi Khalil   +3 more
doaj   +1 more source

On linearization and uniqueness of preduals

Mathematische Nachrichten, Volume 298, Issue 3, Page 955-975, March 2025.
Abstract We study strong linearizations and the uniqueness of preduals of locally convex Hausdorff spaces of scalar‐valued functions. Strong linearizations are special preduals. A locally convex Hausdorff space F(Ω)$\mathcal {F}(\Omega)$ of scalar‐valued functions on a nonempty set Ω$\Omega$ is said to admit a strong linearization if there are a ...
Karsten Kruse
wiley   +1 more source