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One of the most prominent methods for uncertainty quantification in high-dimen-sional statistics is the desparsified LASSO that relies on unconstrained $\ell_1$-minimization. The majority of initial works focused on real (sub-)Gaussian…

Information Theory · Computer Science 2023-09-14 Frederik Hoppe , Felix Krahmer , Claudio Mayrink Verdun , Marion I. Menzel , Holger Rauhut

The statistics of gaps between quantum energy levels is a hallmark criterion in quantum chaos and quantum integrability studies. The relevant distributions corresponding to exactly integrable vs. fully chaotic systems are universal and…

Statistical Mechanics · Physics 2026-04-27 Ben Craps , Marine De Clerck , Oleg Evnin , Maxim Pavlov

Contextuality lays at the heart of quantum mechanics. In the prevailing opinion it is considered as a signature of 'quantumness' that classical theories lack. However, this assertion is only partially justified. Although contextuality is…

Quantum Physics · Physics 2015-02-26 Pawel Blasiak

The Einstein equations are non-linear and the particles of which the gravitational effect is described by these equations are lastly unknown. If renormalizable fields are assumed, then results are obtained only in the case of a at space.…

General Physics · Physics 2016-11-25 Alfred Kording

A quantum-field approach for describing many-particle Fermi systems at finite temperatures and with spontaneously broken symmetry has been proposed. A generalized model of self-consistent field (SCF), which allows one to describe the states…

Statistical Mechanics · Physics 2013-03-21 Yu. M. Poluektov

Starting from the von Neumann-Maxwell equations for the Wigner quasi-probability distribution and for the self-consistent electric field, the quantum analog of the classical single-wave model has been derived. The linear stability of the…

Plasma Physics · Physics 2011-10-24 Stephan I. Tzenov , Kiril B. Marinov

In the theoretical analyses of impurity effects in superconductors the assumption is usually made that all quantities, except for the Green functions, are slowly varying functions of energy. When this so-called Fermi Surface Restricted…

Superconductivity · Physics 2007-05-23 C. T. Rieck , K. Scharnberg , S. Scheffler

A popular model of decoherence based on the linear coupling to harmonic oscillator heat baths is analized and shown to be inappropriate in the regime where decoherence dominates over energy dissipation, called pure decoherence regime. The…

Quantum Physics · Physics 2008-01-08 Robert Alicki

We study decoherence in a simple quantum mechanical model using two approaches. Firstly, we follow the conventional approach to decoherence where one is interested in solving the reduced density matrix from the perturbative master equation.…

Quantum Physics · Physics 2015-05-20 Jurjen F. Koksma , Tomislav Prokopec , Michael G. Schmidt

If we reduce coherence in a given quantum system, the result is an increase in entropy. Does this necessarily convert this quantum system into a classical system? The answer to this question is No. The decrease of coherence means more…

Quantum Physics · Physics 2009-11-06 Y. S. Kim

This paper focuses on defining a measure, appropriate for obtaining optimally sparse solutions to underdetermined systems of linear equations.* The general idea is the extension of metrics in n-dimensional spaces via the Cartesian product…

Optimization and Control · Mathematics 2012-04-24 Leoni Dalla , George K. Papageorgiou

Quantum coherence plays a fundamental and operational role in different areas of physics. A resource theory has been developed to characterize the coherence of distinguishable particles systems. Here we show that indistinguishability of…

Space-time symmetries and internal quantum symmetries can be placed on equal footing in a hyperspin geometry. Four-dimensional classical space-time emerges as a result of a decoherence that disentangles the quantum and the space-time…

Quantum Physics · Physics 2007-05-23 Dorje C. Brody , Lane P. Hughston

We propose a sparse regression method capable of discovering the governing partial differential equation(s) of a given system by time series measurements in the spatial domain. The regression framework relies on sparsity promoting…

Pattern Formation and Solitons · Physics 2016-09-22 Samuel H. Rudy , Steven L. Brunton , Joshua L. Proctor , J. Nathan Kutz

In a recent paper [J. Math. Phys. 47 082303 (2006)], Quantum Energy Inequalities were used to place simple geometrical bounds on the energy densities of quantum fields in Minkowskian spacetime regions. Here, we refine this analysis for…

Mathematical Physics · Physics 2008-11-26 Simon P. Eveson , Christopher J. Fewster

We formulate the Frobenius-norm-based measures for quantum coherence and asymmetry respectively. In contrast to the resource theory of coherence and asymmetry, we construct a natural measure of quantum coherence inspired from optical…

Quantum Physics · Physics 2016-08-31 Yao Yao , G. H. Dong , Xing Xiao , C. P. Sun

We study a model of frustration of decoherence in an open quantum system. Contrary to other dissipative ohmic impurity models, such as the Kondo model or the dissipative two-level system, the impurity model discussed here never presents…

Other Condensed Matter · Physics 2007-05-23 E. Novais , A. H. Castro Neto , L. Borda , I. Affleck , G. Zarand

The claim that there is an inconsistency of quantum-classical dynamics [1] is investigated. We point out that a consistent formulation of quantum and classical dynamics which can be used to describe quantum measurement processes is already…

Quantum Physics · Physics 2007-05-23 E. C. G. Sudarshan

A perturbative treatment of reduced density operators of quantum subsystems is implemented in the same spirit as Fermi Golden Rule for scattering. Analytic expressions for linear entropy (a measure of purity loss, and in some cases of…

Quantum Physics · Physics 2007-05-23 M. O. Terra Cunha , S. Geraij Mokarzel , J. G. Peixoto de Faria , M. C. Nemes

While the slogan "no measurement without disturbance" has established itself under the name Heisenberg effect in the consciousness of the scientifically interested public, a precise statement of this fundamental feature of the quantum world…

Quantum Physics · Physics 2013-10-24 Paul Busch , Pekka Lahti , Reinhard F. Werner