Results 31 to 40 of about 244 (149)

Semi‐Analytical Model of the Rician K‐Factor

Radio Science, Volume 55, Issue 11, November 2020., 2020
Abstract The analysis of the performance of 5G wireless communication systems employing Massive MIMO at millimeter‐wave frequencies is of great practical relevance. Of special relevance are the signal fluctuations. In the present paper, we introduce a semi‐analytical model for a generic scattering environment by using randomly distributed resonant ...
Andrés Alayón Glazunov, Aidin Razavi, Rob Maaskant, Jian Yang   +3 more
wiley   +1 more source

The crossed product of a UHF algebra by a shift [PDF]

Ergodic Theory and Dynamical Systems, 1993
AbstractWe prove that the crossed product of the CAR algebra M2∞ by the shift is an inductive limit of homogeneous algebras over the circle with fibres full matrix algebras. As a consequence the crossed product has real rank zero, and where is the Cuntz algebra of order 2.
Bratteli, Ola, Størmer, Erling, Kishimoto, Akitaka, Rørdam, Mikael   +3 more
openaire   +1 more source

Stability for integer actions on UHF C∗-algebras

Journal of Functional Analysis, 1984
\textit{A. Connes} has given in Acta Sci. Math. 39, 39-66 (1977; Zbl 0382.46027)] a classification of \(Z_ n\) actions on the hyperfinite \(II_ 1\) factor. The authors obtain a norm-continuous version of Connes' solution to 1-cohomology which is adaptable to the \(C^*\)-algebra situation. They also exhibit various model actions which are stable.
Herman, Richard H, Ocneanu, Adrian
openaire   +1 more source

UHF FLOWS AND COCYCLES

, 2012
UHF flows are the flows obtained as inductive limits of flows on full matrix algebras. We will revisit universal UHF flows and give an explicit construction of such flows on a UHF algebra Mk∞ for any k and also present a characterization of such flows ...
A. KISHIMOTO
core   +1 more source

Extreme points in triangular UHF algebras [PDF]

Transactions of the American Mathematical Society, 1997
We examine the strongly extreme point structure of the unit balls of triangular UHF algebras. The semisimple triangular UHF algebras are characterized as those for which this structure is minimal in the sense that every strongly extreme point belongs to the diagonal.
Hudson, Timothy D., Katsoulis, Elias G., Larson, David R.   +2 more
openaire   +1 more source

Automorphisms and Dilation Theory of Triangular UHF Algebras [PDF]

Integral Equations and Operator Theory, 2013
We study the triangular subalgebras of UHF algebras which provide new examples of algebras with the Dirichlet property and the Ando property. This in turn allows us to describe the semicrossed product by an isometric automorphism. We also study the isometric automorphism group of these algebras and prove that it decomposes into the semidirect product ...
openaire   +3 more sources

Software Update: The ORCA Program System—Version 6.0

WIREs Computational Molecular Science, Volume 15, Issue 2, March/April 2025.
This article describes the philosophy behind‐ and new features in the ORCA quantum chemistry program suite, version 6.0. ABSTRACT Version 6.0 of the ORCA quantum chemistry program suite was released in July 2024. ORCA 6.0 is a major turning point in the history of the program since it represents a near complete rewrite of the code base that leads to ...
Frank Neese
wiley   +1 more source

Completely positive maps of order zero [PDF]

, 2009
We say a completely positive contractive map between two C^*-algebras has order zero, if it sends orthogonal elements to orthogonal elements. We prove a structure theorem for such maps. As a consequence, order zero maps are in one-
Winter, W. (Wilhelm), Zacharias, J. (Joachim), Zacharias, J., Winter, W.   +3 more
core  

Nonseparable UHF algebras I: Dixmier's problem

Advances in Mathematics, 2010
There are three natural ways to define UHF (uniformly hyperfinite) C*-algebras, and all three definitions are equivalent for separable algebras. In 1967 Dixmier asked whether the three definitions remain equivalent for not necessarily separable algebras. We give a complete answer to this question.
Farah, Ilijas, Katsura, Takeshi
openaire   +3 more sources

Equation‐of‐motion orbital‐optimized coupled‐cluster doubles method with the density‐fitting approximation: An efficient implementation

Journal of Computational Chemistry, Volume 45, Issue 32, Page 2969-2978, December 15, 2024.
The computational cost of the DF‐EOM‐OCCD method for excitation energies is compared with that of the conventional EOM‐OCCD method. Our results demonstrate that DF‐EOM‐OCCD excitation energies are dramatically accelerated compared to EOM‐OCCD. There are almost 17‐fold reductions for the C5H12 molecule in a aug‐cc‐pVTZ basis set with the RHF reference ...
Aslı Ünal, Uğur Bozkaya
wiley   +1 more source