Results 51 to 60 of about 2,806 (244)

Singular Perturbations of Self-Adjoint Operators [PDF]

Mathematical Physics, Analysis and Geometry, 2003
Let \(A_0\) be a self-adjoint operator in a Hilbert space \(\mathcal H\) and denote by \({\mathcal H}_s(A)\), \(s\in{\mathbb R}\), the scale of Hilbert spaces associated with \(A_0\). Singular finite rank perturbations of \(A_0\) are defined formally as \(A_{(\alpha)}=A_0+G\alpha G^*\), where \(G\) is an injective linear mapping from \(H={\mathbb C}^d\)
Derkach, V, Hassi, Seppo, De Snoo, H
openaire   +2 more sources

Optimal Portfolio Choice With Cross‐Impact Propagators

Mathematical Finance, EarlyView.
ABSTRACT We consider a class of optimal portfolio choice problems in continuous time where the agent's transactions create both transient cross‐impact driven by a matrix‐valued Volterra propagator, as well as temporary price impact. We formulate this problem as the maximization of a revenue‐risk functional, where the agent also exploits available ...
Eduardo Abi Jaber, Eyal Neuman, Sturmius Tuschmann   +2 more
wiley   +1 more source

Degree theory for 4‐dimensional asymptotically conical gradient expanding solitons

Communications on Pure and Applied Mathematics, Volume 79, Issue 5, Page 1151-1298, May 2026.
Abstract We develop a new degree theory for 4‐dimensional, asymptotically conical gradient expanding solitons. Our theory implies the existence of gradient expanding solitons that are asymptotic to any given cone over S3$S^3$ with non‐negative scalar curvature. We also obtain a similar existence result for cones whose link is diffeomorphic to S3/Γ$S^3/\
Richard H. Bamler, Eric Chen
wiley   +1 more source

Maximal Function Characterizations of Variable Hardy Spaces Associated with Non-negative Self-adjoint Operators Satisfying Gaussian Estimates [PDF]

, 2016
Let $p(\cdot):\ \mathbb R^n\to(0,1]$ be a variable exponent function satisfying the globally $\log$-H\"older continuous condition and $L$ a non-negative self-adjoint operator on $L^2(\mathbb R^n)$ whose heat kernels satisfying the Gaussian upper bound ...
Ciqiang Zhuo, Dachun Yang
semanticscholar   +1 more source

Isoperimetric inequalities on slabs with applications to cubes and Gaussian slabs

Communications on Pure and Applied Mathematics, Volume 79, Issue 4, Page 1012-1072, April 2026.
Abstract We study isoperimetric inequalities on “slabs”, namely weighted Riemannian manifolds obtained as the product of the uniform measure on a finite length interval with a codimension‐one base. As our two main applications, we consider the case when the base is the flat torus R2/2Z2$\mathbb {R}^2 / 2 \mathbb {Z}^2$ and the standard Gaussian measure
Emanuel Milman
wiley   +1 more source

Non-symmetric perturbations of self-adjoint operators [PDF]

, 2016
We investigate the effect of non-symmetric relatively bounded perturbations on the spectrum of self-adjoint operators. In particular, we establish stability theorems for one or infinitely many spectral gaps along with corresponding resolvent estimates ...
Jean-Claude Cuenin, C. Tretter
semanticscholar   +1 more source

The nonlocal problem for the $2n$ differential equations with unbounded operator coefficients and the involution

Karpatsʹkì Matematičnì Publìkacìï, 2018
We study a problem with periodic boundary conditions for a $2n$-order differential equation whose coefficients are non-self-adjoint operators. It is established that the operator of the problem has two invariant subspaces generated by the involution ...
Ya.O. Baranetskij, I.I. Demkiv, I.Ya. Ivasiuk, M.I. Kopach   +3 more
doaj   +1 more source

Hybrid Reaction–Diffusion Epidemic Models: Dynamics and Emergence of Oscillations

Mathematical Methods in the Applied Sciences, Volume 49, Issue 5, Page 4074-4095, 30 March 2026.
ABSTRACT In this paper, we construct a hybrid epidemic mathematical model based on a reaction–diffusion system of the SIR (susceptible‐infected‐recovered) type. This model integrates the impact of random factors on the transmission rate of infectious diseases, represented by a probabilistic process acting at discrete time steps.
Asmae Tajani, Cristiana J. Silva, Guillaume Cantin   +2 more
wiley   +1 more source

Small-energy analysis for the self-adjoint matrix Schrodinger operator on the half line [PDF]

, 2011
The matrix Schrodinger equation with a self-adjoint matrix potential is considered on the half line with the most general self-adjoint boundary condition at the origin.
T. Aktosun, M. Klaus, R. Weder
semanticscholar   +1 more source

The Regularized Trace Formula Of A Second Order Differentıal Equation Given With Anti-Perıodic Boundary Conditions

Cumhuriyet Science Journal, 2019
In this study, we examined the formula of the regularizedtrace of the self-adjoint operator which is formed bydifferentialexpression and anti-periodic boundary condition.
Seda Kızılbudak Çalışkan, Leyla Özen   +1 more
doaj   +1 more source