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Two-component linear-response time-dependent density functional theory (TDDFT) provides a unified framework that encompasses noncollinear excitations in noncollinear reference states, as well as both spin-conserving and spin-flip…

Chemical Physics · Physics 2026-04-30 Xiaoyu Zhang

We discuss heterotic string theories in two dimensions with gauge groups Spin(24) and Spin(8) x E_8. After compactification the theories exhibit a rich spectrum of states with both winding and momentum. At special points some of these…

High Energy Physics - Theory · Physics 2009-11-11 Joshua L. Davis , Finn Larsen , Nathan Seiberg

The power spectral density (PSD) is a central frequency-domain descriptor of stochastic processes. While PSDs have been studied for Brownian motion and a few anomalous diffusion processes, the spectral densities of active nonequilibrium…

Statistical Mechanics · Physics 2026-05-12 Yeongjin Kim , Gleb Oshanin , Jae-Hyung Jeon

Time-dependent density-functional theory (TDDFT) is widely used to describe electronic excitations in complex finite systems with large numbers of atoms, such as biomolecules and nanocrystals. The first part of this paper will give a simple…

Materials Science · Physics 2008-08-15 C. A. Ullrich , V. Turkowski

The selection of an equilibrium state by maximising the entropy of a system, subject to certain constraints, is often powerfully motivated as an exercise in logical inference, a procedure where conclusions are reached on the basis of…

Statistical Mechanics · Physics 2015-12-03 Ian J. Ford

The Einstein-Cartan-Saa theory of torsion modifies the spacetime volume element so that it is compatible with the connection. The condition of connection compatibility gives constraints on torsion, which are also necessary for the…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Nikodem J. Poplawski

We study a generalized two-species model on a ring. The original model [1] describes ordinary particles hopping exclusively in one direction in the presence of an impurity. The impurity hops with a rate different from that of ordinary…

Statistical Mechanics · Physics 2009-10-31 Farhad H Jafarpour

The propagation of electrostatic waves in an unmagnetized collisionless pair-ion plasma with immobile positively charged dusts is studied for both large- and small-amplitude perturbations. Using a two-fluid model for pair-ions, it is shown…

Plasma Physics · Physics 2013-10-18 A. P. Misra , N. C. Adhikary

Gade [R. Gade, Nucl. Phys. B \textbf{398}, 499 (1993)] has shown that the local density of states for a particle hopping on a two-dimensional bipartite lattice in the presence of weak disorder and in the absence of time-reversal…

Condensed Matter · Physics 2009-11-07 C. Mudry , S. Ryu , A. Furusaki

The formalism developed in the first paper of the series [arXiv:0901.1060] is applied to two thermodynamic systems: (i) of three global observables (the energy, the total electron number and the spin number), (ii) of one global observable…

Chemical Physics · Physics 2013-10-28 Robert Balawender , Andrzej Holas

We consider 2D Dirac fermions in the presence of three types of disorder: random scalar potential, random gauge potential and random mass with long-range correlations decaying as a power law. Using various methods such as the…

Mesoscale and Nanoscale Physics · Physics 2012-03-29 Andrei A. Fedorenko , David Carpentier , Edmond Orignac

The strength functions of quadrupole modes in the unstable oxygen isotopes 22O and 24O are calculated using an extended version of the time-dependent Hartree-Fock theory known as the time-dependent density-matrix theory (TDDM). It is found…

Nuclear Theory · Physics 2009-11-07 M. Tohyama , A. S. Umar

Persistent excitation (PE) is a necessary and sufficient condition for uniform exponential parameter convergence in several adaptive, identification, and learning schemes. In this article, we consider, in the context of multi-input linear…

Systems and Control · Electrical Eng. & Systems 2025-02-07 Marco Borghesi , Simone Baroncini , Guido Carnevale , Alessandro Bosso , Giuseppe Notarstefano

While the variational principle for excited-state energies leads to a route to obtaining excited-state densities from time-dependent density functional theory, relatively little attention has been paid to the quality of the resulting…

Chemical Physics · Physics 2025-09-12 Anna Baranova , Neepa T. Maitra

Effective stochastic resonance (SR) is numerically and analytically studied using a model with coupled two particles exposed to heterogeneous, i.e., particles dependent, amplitude of noise. Compared to previous SR models of single particle…

Statistical Mechanics · Physics 2010-04-28 Shogo Torigoe , Ryosuke Kawai , Kazuhiro Yoshida , Akinori Awazu , Hiraku Nishimori

Excited state decay is examined within the framework of strictly Everett-like (SEL) formulations of quantum mechanics. Even though these formulations were developed for systems of particles as part of a larger system that includes a…

Quantum Physics · Physics 2012-09-18 Jon Geist

We introduce a novel set of stability conditions for vacua with broken Lorentz symmetry. The first class of conditions require that the energy be minimized under small geometric deformations, which translates into requiring the positivity…

High Energy Physics - Theory · Physics 2015-06-16 Sophia K. Domokos , Carlos Hoyos , Jacob Sonnenschein

The Steepest Entropy Ascent approach is considered and applied to few-state systems. When the Hamiltonian of the system is time dependent, the principle of maximum entropy production can still be exploited; arguments to support this fact…

Quantum Physics · Physics 2018-07-10 Benedetto Militello

Pseudorandom states (PRSs) are state ensembles that cannot be efficiently distinguished from Haar random states. However, the definition of PRSs has been limited to pure states and lacks robustness against noise. Here, we introduce…

Quantum Physics · Physics 2025-05-26 Nikhil Bansal , Wai-Keong Mok , Kishor Bharti , Dax Enshan Koh , Tobias Haug

In this paper, we focus on discrete-time stochastic systems modelled by nonlinear stochastic difference equations and propose robust abstractions for verifying probabilistic linear temporal specifications. The current literature focuses on…

Probability · Mathematics 2022-05-05 Yiming Meng , Jun Liu