Results 51 to 60 of about 831,773 (152)

Shape Derivatives of the Eigenvalues of the De Rham Complex for Lipschitz Deformations and Variable Coefficients: Part I

Mathematical Methods in the Applied Sciences, Volume 49, Issue 8, Page 7975-8005, 30 May 2026.
ABSTRACT We study eigenvalue problems for the de Rham complex on varying three‐dimensional domains. Our analysis includes the Helmholtz equation as well as the Maxwell system with mixed boundary conditions and non‐constant coefficients. We provide Hadamard‐type formulas for the shape derivatives under weak regularity assumptions on the domain and its ...
Pier Domenico Lamberti, Dirk Pauly, Michele Zaccaron   +2 more
wiley   +1 more source

On some variational problems in the theory of unitarily invariant norms and Hadamard products [PDF]

, 2001
We deal with two recent conjectures of R.-C. Li [Linear Algebra Appl. 278 (1998) 317–326], involving unitarily invariant norms and Hadamard products.
Romeo, M., Paolo Tilli, Tilli, Paolo, Romeo, Mario, Mario Romeo, ROMEO M   +5 more
core   +1 more source

Countable Basis for Free Electromagnetic Fields

Annalen der Physik, Volume 538, Issue 5, May 2026.
ABSTRACT Polychromatic electromagnetic fields are expanded as integrals over monochromatic fields, such as plane waves, multipolar fields, or Bessel beams. However, monochromatic fields do not belong to the Hilbert space of free Maxwell fields, since their norms diverge.
Ivan Fernandez‐Corbaton
wiley   +1 more source

Maximally dissipative and self‐adjoint extensions of K$K$‐invariant operators

Bulletin of the London Mathematical Society, Volume 58, Issue 5, May 2026.
Abstract We introduce the notion of K$K$‐invariant operators, S$S$, in a Hilbert space, with respect to a bounded and boundedly invertible operator K$K$ defined via K∗SK=S$K^*SK=S$. Conditions such that self‐adjoint and maximally dissipative extensions of K$K$‐invariant symmetric operators are also K$K$‐invariant are investigated.
Christoph Fischbacher, Bart Rosenzweig, Jonathan Stanfill   +2 more
wiley   +1 more source

Enhanced Young-type inequalities utilizing Kantorovich approach for semidefinite matrices

Open Mathematics
This article introduces new Young-type inequalities, leveraging the Kantorovich constant, by refining the original inequality. In addition, we present a range of norm-based inequalities applicable to positive semidefinite matrices, such as the Hilbert ...
Bani-Ahmad Feras, Rashid Mohammad Hussein Mohammad   +1 more
doaj   +1 more source

Some inequalities involving unitarily invariant norms [PDF]

Mathematical Inequalities & Applications, 2012
This paper aims to present some inequalities for unitarily invariant norms. We first give inverses of Young and Heinz type inequalities for scalars. Then we use these inequalities to establish some inequalities for unitarily invariant norms. Mathematics subject classification (2010): 15A45, 15A60.
Chuanjiang He, Limin Zou
openaire   +1 more source

Algebraic singular functions are not always dense in the ideal of C∗$C^*$‐singular functions

Bulletin of the London Mathematical Society, Volume 58, Issue 5, May 2026.
Abstract We give the first examples of étale (non‐Hausdorff) groupoids G$\mathcal {G}$ whose C∗$C^*$‐algebras contain singular elements that cannot be approximated by singular elements in Cc(G)$\mathcal {C}_c(\mathcal {G})$. We provide two examples: one is a bundle of groups and the other a minimal and effective groupoid constructed from a self‐similar
Diego Martínez, Nóra Szakács
wiley   +1 more source

Quantum Time‐Marching Algorithms for Solving Linear Transport Problems Including Boundary Conditions

International Journal for Numerical Methods in Engineering, Volume 127, Issue 8, 30 April 2026.
ABSTRACT This article presents the first complete application of a quantum time‐marching algorithm for simulating multidimensional linear transport phenomena with arbitrary boundaries, whereby the success probabilities are problem intrinsic. The method adapts the linear combination of unitaries algorithm to block encode the diffusive dynamics, while ...
Sergio Bengoechea, Paul Over, Thomas Rung   +2 more
wiley   +1 more source

Non‐Relativistic Limit of Dirac Hamiltonians With Aharonov–Bohm Fields

Studies in Applied Mathematics, Volume 156, Issue 4, April 2026.
ABSTRACT We characterize the families of self‐adjoint Dirac and Schrödinger operators with Aharonov–Bohm magnetic field, and we exploit the non‐relativistic limit of infinite light speed to connect the former to the latter. The limit consists of the customary removal of the rest energy and of a suitable scaling, with the light speed, of the short‐scale
Matteo Gallone, Alessandro Michelangeli, Diego Noja   +2 more
wiley   +1 more source

Disentanglement by Deranking and by Suppression of Correlation

Advanced Quantum Technologies, Volume 9, Issue 3, March 2026.
ABSTRACT The spontaneous disentanglement hypothesis is motivated by some outstanding issues in standard quantum mechanics, including the problem of quantum measurement. The current study compares between some possible methods that can be used to implement the hypothesis.
Eyal Buks
wiley   +1 more source