English
Related papers

Related papers: Instability of q-expectation value

200 papers

This paper considers the problem of robust stability for a class of uncertain quantum systems subject to unknown perturbations in the system coupling operator. A general stability result is given for a class of perturbations to the system…

Quantum Physics · Physics 2012-08-31 Ian R. Petersen , Valery Ugrinovskii , Matthew R. James

The notion of "closed systems" in Quantum Mechanics is discussed. For this purpose, we study two models of a quantum-mechanical system $P$ spatially far separated from the "rest of the universe" $Q$. Under reasonable assumptions on the…

Mathematical Physics · Physics 2015-05-06 Jérémy Faupin , Jürg Fröhlich , Baptiste Schubnel

Deviations of the decay law from exponents are discussing for a long time, however, experimental proofs of such deviations are absent. Here in the general form is shown that the conclusions about non-exponential contributions are due to the…

Quantum Physics · Physics 2009-11-13 Sergei G. Matinyan , Mark E. Perel'man

The best mathematical arguments against a realistic interpretation of quantum mechanics - that gives definite but partially unknown values to all observables - are analysed and shown to be based on reasoning that is not compelling. This…

Quantum Physics · Physics 2007-05-23 Arnold Neumaier

We give a mathematical definition for the notion of inconclusive quantum measurements. In physics, such measurements occur at intermediate stages of a complex measurement procedure, with the final measurement result being operationally…

Quantum Physics · Physics 2016-04-19 V. I. Yukalov , D. Sornette

We examine the dynamics of a particle in a general rotating quadratic potential, not necessarily stable or isotropic, using a general complex mode formalism. The problem is equivalent to that of a charged particle in a quadratic potential…

Quantum Physics · Physics 2015-06-03 R. Rossignoli , A. M. Kowalski

An unstable quantum state generally decays following an exponential law, as environmental decoherence is expected to prevent the decay products from recombining to reconstruct the initial state. Here we show the existence of deviations from…

Quantum Physics · Physics 2017-10-02 M. Beau , J. Kiukas , I. L. Egusquiza , A. del Campo

To explore the limits of a stochastic gradient method, it may be useful to consider an example consisting of an infinite number of quadratic functions. In this context, it is appropriate to determine the expected value and the covariance…

Optimization and Control · Mathematics 2022-12-14 Melinda Hagedorn

Starting on the basis of the non-commutative q-differential calculus, we introduce a generalized q-deformed Schr\"odinger equation. It can be viewed as the quantum stochastic counterpart of a generalized classical kinetic equation, which…

Mathematical Physics · Physics 2009-11-13 A. Lavagno

During the past few years, nonextensive statistics has been successfully applied to explain many different kinds of systems. Through these studies some interpretations of the entropic parameter q, which has major role in this statistics, in…

Statistical Mechanics · Physics 2011-07-01 D. O. Soares-Pinto , M. S. Reis , R. S. Sarthour , I. S. Oliveira

The properties of the nonextensive parameter q and the Tsallis distribution for self-gravitating systems are studied. A mathematical expression of q is deduced based on the generalized Boltzmann equation, the q-H theorem and the generalized…

Statistical Mechanics · Physics 2015-08-10 Jiulin Du

We consider deformations of quantum mechanical operators by using the novel construction of warped convolutions. The deformation enables us to obtain several quantum mechanical effects where electromagnetic and gravitomagnetic fields play a…

Mathematical Physics · Physics 2014-02-19 Albert Much

A variety of physical unknowables are discussed. Provable lack of physical omniscience, omnipredictability and omnipotence is derived by reduction to problems which are known to be recursively unsolvable. "Chaotic" symbolic dynamical…

General Physics · Physics 2011-07-22 Karl Svozil

Consider a statistical model with an epistemic restriction such that, unlike in classical mechanics, the allowed distribution of positions is fundamentally restricted by the form of an underlying momentum field. Assume an agent (observer)…

Quantum Physics · Physics 2020-05-15 Agung Budiyono

We study numerically a class of non-topological solitons, the Q-balls, arising in supersymmetric extension of the Standard Model with low-energy, gauge-mediated symmetry breaking. % Taking into account the exact form of the supersymmetric…

High Energy Physics - Theory · Physics 2008-11-26 L. Campanelli , M. Ruggieri

The full algebra of relativistic quantum mechanics (Lorentz plus Heisenberg) is unstable. Stabilization by deformation leads to a new deformation parameter $\epsilon \ell ^{2}$, $\ell $ being a length and $\epsilon$ a $\pm$ sign. The…

Quantum Physics · Physics 2009-11-07 Eric Carlen , R. Vilela Mendes

The quantum theory (QT) and new stochastic approaches have no deterministic prediction for a single measurement or for a single time -series of events observed for a trapped ion, electron or any other individual physical system. The…

Quantum Physics · Physics 2013-12-04 Marian Kupczynski

Fractional derivative and delay are important tools in modeling memory properties in the natural system. This work deals with the stability analysis of a fractional order delay differential equation \begin{equation*} D^\alpha x(t)=\delta…

Dynamical Systems · Mathematics 2022-08-29 Sachin Bhalekar , Deepa Gupta

The quantum mechanics is considered to be a partial case of the stochastic system dynamics. It is shown that the wave function describes the state of statistically averaged system $<\mathcal{S}_{st}>$, but not that of the individual…

General Physics · Physics 2007-05-23 Yuri A. Rylov

We discuss stability of Q-balls interacting with fermions in theory with small coupling constant g. We argue that for configurations with large global U(1)-charge Q the problem of classical stability becomes more subtle. For example, in…

High Energy Physics - Phenomenology · Physics 2017-11-23 A. V. Kovtun , E. Ya. Nugaev