Results 31 to 40 of about 2,915 (59)

Flat connections and Wigner-Yanase-Dyson metrics

, 2003
On the manifold of positive definite matrices, we investigate the existence of pairs of flat affine connections, dual with respect to a given monotone metric.
Amari, Amari, Amari, Anna Jenčová, Bhatia, Chentsov, Chentsov, Dittmann, Dittmann, Eguchi, Grasselli, Hasegawa, Hasegawa, Hasegawa, Hasegawa, Jenčová, Jenčová, Lesniewski, Nagaoka, Petz, Petz, Petz   +21 more
core   +2 more sources

Octonionic Magical Supergravity, Niemeier Lattices, and Exceptional & Hilbert Modular Forms

Fortschritte der Physik, Volume 72, Issue 2, February 2024.
Abstract The quantum degeneracies of Bogomolny‐Prasad‐Sommerfield (BPS) black holes of octonionic magical supergravity in five dimensions are studied. Quantum degeneracy is defined purely number theoretically as the number of distinct states in charge space with a given set of invariant labels.
Murat Günaydin, Abhiram Kidambi
wiley   +1 more source

Entanglement properties of bound and resonant few-body states

, 2018
Studying the physics of quantum correlations has gained new interest after it has become possible to measure entanglement entropies of few body systems in experiments with ultracold atomic gases. Apart from investigating trapped atom systems, research on
Amico, Amovilli, Balslev, Bednarek, Benenti, Bohm, Bohm, Bouvrie, Brody, Brändas, Civitarese, Coleman, Collins, Dehesa, Gamow, Glasser, Hess, Islam, Jacak, Janzing, Kais, Kato, Kościk, Kościk, Kościk, Kościk, Kuroś, Kuroś, Kuroś, Lin, López-Rosa, Löwdin, Löwdin, Löwdin, Manzano, Moiseyev, Moiseyev, Nagy, Nielsen, Okopińska, Okopińska, Osenda, Pont, Reinhardt, Rescigno, Rotter, Tichy, Wigner, Yañez, Ziesche   +49 more
core   +1 more source

Developing HSS iteration schemes for solving the quadratic matrix equation AX2+BX+C=0$AX^{2}+BX+C=0$

IET Control Theory &Applications, Volume 18, Issue 3, Page 335-349, February 2024.
The quadratic matrix equation (QME) Q(X)=AX2+BX+C,$$\begin{equation*} Q(X)=AX^{2}+BX+C, \end{equation*}$$occurs in the branches such as the quadratic eigenvalue problems and quasi‐birth‐death processes. Also, the numerical solution of QMEs is an essential step in many computational methods for linear‐ quadratic and robust control, filtering, controller
Raziyeh Erfanifar, Masoud Hajarian
wiley   +1 more source

Generalized Random Phase Approximation and Gauge Theories

, 2003
Mean-field treatments of Yang-Mills theory face the problem of how to treat the Gauss law constraint. In this paper we try to face this problem by studying the excited states instead of the ground state.
Aouissat, Aouissat, Aouissat, Brown, Christ, Csaki, de la Torre, de Mello Koch, Dirac, Dirac, Fischer, Goldstein, Greensite, Heinemann, Hugo Reinhardt, Jackiw, Kerman, Kerman, Kerman, Kerman, Kerman, Kogan, Lavelle, Lee, Marshalek, Marshallek, Marshallek, Minahan, Nesbet, Oliver Schröder, Reinhardt, Ring, Rowe, Soloviev, Teper, Thouless, Thouless, Thouless, Zarembo   +38 more
core   +1 more source

Why diffusion‐based preconditioning of Richards equation works: Spectral analysis and computational experiments at very large scale

Numerical Linear Algebra with Applications, Volume 31, Issue 1, January 2024.
Abstract We consider here a cell‐centered finite difference approximation of the Richards equation in three dimensions, averaging for interface values the hydraulic conductivity K=K(p)$$ K=K(p) $$, a highly nonlinear function, by arithmetic, upstream and harmonic means.
Daniele Bertaccini, Pasqua D'Ambra, Fabio Durastante, Salvatore Filippone   +3 more
wiley   +1 more source

The cryptohermitian smeared-coordinate representation of wave functions

, 2011
The one-dimensional real line of coordinates is replaced, for simplification or approximation purposes, by an N-plet of the so called Gauss-Hermite grid points. These grid points are interpreted as the eigenvalues of a tridiagonal matrix $\mathfrak{q}_0$
Abramowitz, Bender, Bender, Buslaev, Char, Dieudonné, Hilgevoord, Langer, Lévai, Miloslav Znojil, Mostafazadeh, Mostafazadeh, Mostafazadeh, Mostafazadeh, Mustafa, Scholtz, Sinha, Smilga, Stoer, Znojil, Znojil, Znojil, Znojil   +22 more
core   +1 more source

Impact of correlated observation errors on the conditioning of variational data assimilation problems

Numerical Linear Algebra with Applications, Volume 31, Issue 1, January 2024.
Summary An important class of nonlinear weighted least‐squares problems arises from the assimilation of observations in atmospheric and ocean models. In variational data assimilation, inverse error covariance matrices define the weighting matrices of the least‐squares problem.
Olivier Goux, Selime Gürol, Anthony T. Weaver, Youssef Diouane, Oliver Guillet   +4 more
wiley   +1 more source

Dynamical stability criterion for inhomogeneous quasi-stationary states in long-range systems

, 2010
We derive a necessary and sufficient condition of linear dynamical stability for inhomogeneous Vlasov stationary states of the Hamiltonian Mean Field (HMF) model.
Alessandro Campa, Antonov V A, Arnol’d V I, Arnol’d V I, Balescu R, Bartholomew P, Binney J, Campa A, Chavanis P H, Chavanis P H, Chavanis P H Campa A, Dauxois T, Ellis R, Elskens Y, Inagaki S, Konishi T, Lemou M Méhats F Raphael P, Lynden-Bell D, Nicholson D R, Pierre-Henri Chavanis, Tremaine S   +20 more
core   +3 more sources

Polaritonic response theory for exact and approximate wave functions

WIREs Computational Molecular Science, Volume 14, Issue 1, January/February 2024.
The theory behind polaritonic chemistry is discussed from a single‐molecule chemical perspective. We derive a response framework for quantum electrodynamics and provide approximate response equations for ab initio QED‐HF and QED‐CC. Abstract Polaritonic chemistry is an interdisciplinary emerging field that presents several challenges and opportunities ...
Matteo Castagnola, Rosario Roberto Riso, Alberto Barlini, Enrico Ronca, Henrik Koch   +4 more
wiley   +1 more source