Quantum Gravitational Decoherence from Fluctuating Minimal Length And
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Yes, More Decoherence: a Reply to Critics
Yes, More Decoherence: A Reply to Critics Elise M. Crull∗ Submitted 11 July 2017; revised 24 August 2017 1 Introduction A few years ago I published an article in this journal titled \Less interpretation and more decoherence in quantum gravity and inflationary cosmology" (Crull, 2015) that generated replies from three pairs of authors: Vassallo and Esfeld (2015), Okon and Sudarsky (2016) and Fortin and Lombardi (2017). As a philosopher of physics it is my chief aim to engage physicists and philosophers alike in deeper conversation regarding scientific theories and their implications. In as much as my earlier paper provoked a suite of responses and thereby brought into sharper relief numerous misconceptions regarding decoherence, I welcome the occasion provided by the editors of this journal to continue the discussion. In what follows, I respond to my critics in some detail (wherein the devil is often found). I must be clear at the outset, however, that due to the nature of these criticisms, much of what I say below can be categorized as one or both of the following: (a) a repetition of points made in the original paper, and (b) a reiteration of formal and dynamical aspects of quantum decoherence considered uncontroversial by experts working on theoretical and experimental applications of this process.1 I begin with a few paragraphs describing what my 2015 paper both was, and was not, about. I then briefly address Vassallo's and Esfeld's (hereafter VE) relatively short response to me, dedicating the bulk of my reply to the lengthy critique of Okon and Sudarsky (hereafter OS). -
A Closure Scheme for Chemical Master Equations
A closure scheme for chemical master equations Patrick Smadbeck and Yiannis N. Kaznessis1 Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, MN 55455 Edited by Wing Hung Wong, Stanford University, Stanford, CA, and approved July 16, 2013 (received for review April 8, 2013) Probability reigns in biology, with random molecular events dictating equation governs the evolution of the probability, PðX; tÞ,thatthe the fate of individual organisms, and propelling populations of system is at state X at time t: species through evolution. In principle, the master probability À Á equation provides the most complete model of probabilistic behavior ∂P X; t X À Á À Á À Á À Á = T X X′ P X′; t − T X′ X P X; t : [1] in biomolecular networks. In practice, master equations describing ∂t complex reaction networks have remained unsolved for over 70 X′ years. This practical challenge is a reason why master equations, for À Á all their potential, have not inspired biological discovery. Herein, we This is a probability conservation equation, where T X X′ is present a closure scheme that solves the master probability equation the transition propensity from any possible state X′ to state X of networks of chemical or biochemical reactions. We cast the master per unit time. In a network of chemical or biochemical reactions, equation in terms of ordinary differential equations that describe the the transition probabilities are defined by the reaction-rate laws time evolution of probability distribution moments. We postulate as a set of Poisson-distributed reaction propensities; these simply that a finite number of moments capture all of the necessary dictate how many reaction events take place per unit time. -
Uncertainty Relation on a World Crystal and Its Applications to Micro Black Holes
PHYSICAL REVIEW D 81, 084030 (2010) Uncertainty relation on a world crystal and its applications to micro black holes Petr Jizba,1,2,* Hagen Kleinert,1,† and Fabio Scardigli3,‡ 1ITP, Freie Universita¨t Berlin, Arnimallee 14 D-14195 Berlin, Germany 2FNSPE, Czech Technical University in Prague, Brˇehova´ 7, 115 19 Praha 1, Czech Republic 3Leung Center for Cosmology and Particle Astrophysics (LeCosPA), Department of Physics, National Taiwan University, Taipei 106, Taiwan (Received 17 December 2009; published 16 April 2010) We formulate generalized uncertainty relations in a crystal-like universe—a ‘‘world crystal’’—whose lattice spacing is of the order of Planck length. In the particular case when energies lie near the border of the Brillouin zone, i.e., for Planckian energies, the uncertainty relation for position and momenta does not pose any lower bound on involved uncertainties. We apply our results to micro black holes physics, where we derive a new mass-temperature relation for Schwarzschild micro black holes. In contrast to standard results based on Heisenberg and stringy uncertainty relations, our mass-temperature formula predicts both a finite Hawking’s temperature and a zero rest-mass remnant at the end of the micro black hole evaporation. We also briefly mention some connections of the world-crystal paradigm with ’t Hooft’s quantization and double special relativity. DOI: 10.1103/PhysRevD.81.084030 PACS numbers: 04.70.Dy, 03.65. w À I. INTRODUCTION from numerical computations. One may, however, inves- tigate the consequences of taking the lattice no longer as a Recent advances in gravitational and quantum physics mere computational device, but as a bona fide discrete indicate that in order to reconcile the two fields with each network, whose links define the only possible propagation other, a dramatic conceptual shift is required in our under- directions for signals carrying the interactions between standing of spacetime. -
Emergent Gravity As the Nematic Dual of Lorentz-Invariant Elasticity
SMR 1646 - 12 ___________________________________________________________ Conference on Higher Dimensional Quantum Hall Effect, Chern-Simons Theory and Non-Commutative Geometry in Condensed Matter Physics and Field Theory 1 - 4 March 2005 ___________________________________________________________ Emergent gravity as the nematic dual of Lorentz-invariant Elasticity Johannes ZAANEN Stanford Univ., Stanford, U.S.A. ___________________________________________________________________ These are preliminary lecture notes, intended only for distribution to participants. EmergentEmergent gravitygravity asas thethe nematicnematic dualdual ofof LorentzLorentz--invariantinvariant ElasticityElasticityTalk Jan Zaanen Hagen Kleinert Sergei Mukhin Zohar Nussinov Vladimir Cvetkovic 1 Emergent Einstein Gravity c 3 S =− dV −g R + S 16πG ∫ matter Einstein’s space time = the Lorentz invariant topological nematic superfluid (at least in 2+1D) A medium characterized by: - emergent general covariance - absence of torsion- and compressional rigidity - presence of curvature rigidity (topological order) 2 Plan of talk 1. Plasticity (defected elasticity) and differential geometry 2. Fluctuating order and high Tc superconductivity 3. Dualizing non-relativistic quantum elasticity 3.a Quantum nematic orders 3.b Superconductivity: dual Higgs is Higgs 4. The quantum nematic world crystal and Einstein’s space time 3 Quantum-elasticity: basics Quantum elastic action, isotropic medium ν ⎡ 2 2 2 2 2 2⎤ S = µ u + 2u + u + ()u + u + ()∂τ u + ()∂τ u ⎣⎢ xx xy yy 1−ν xx yy x y ⎦⎥ Shear modulus µ, Poisson ratio ν, compression modulus κ = µ()1 + ν /1()− ν 2 = µ ρ = = = ()∂ + ∂ c ph 2 / 1, h 1, uab a ub b ua /2 Describes transversal- (T) and longitudinal (L) phonon, 2 2 ⎡⎛ q ⎞ ⎛ q ⎞ ⎤ S = µ ⎢⎜ + ω 2 ⎟ | uT |2 +⎜ + ω 2 ⎟ | uL |2⎥ ⎣⎝ 2 ⎠ ⎝ 1−ν ⎠ ⎦ 4 Elasticity and topology: the dislocation J.M. -
Fluctuations of Spacetime and Holographic Noise in Atomic Interferometry
General Relativity and Gravitation (2011) DOI 10.1007/s10714-010-1137-7 RESEARCHARTICLE Ertan Gokl¨ u¨ · Claus Lammerzahl¨ Fluctuations of spacetime and holographic noise in atomic interferometry Received: 10 December 2009 / Accepted: 12 December 2010 c Springer Science+Business Media, LLC 2010 Abstract On small scales spacetime can be understood as some kind of space- time foam of fluctuating bubbles or loops which are expected to be an outcome of a theory of quantum gravity. One recently discussed model for this kind of space- time fluctuations is the holographic principle which allows to deduce the structure of these fluctuations. We review and discuss two scenarios which rely on the holo- graphic principle leading to holographic noise. One scenario leads to fluctuations of the spacetime metric affecting the dynamics of quantum systems: (i) an appar- ent violation of the equivalence principle, (ii) a modification of the spreading of wave packets, and (iii) a loss of quantum coherence. All these effects can be tested with cold atoms. Keywords Quantum gravity phenomenology, Holographic principle, Spacetime fluctuations, UFF, Decoherence, Wavepacket dynamics 1 Introduction The unification of quantum mechanics and General Relativity is one of the most outstanding problems of contemporary physics. Though yet there is no theory of quantum gravity. There are a lot of reasons why gravity must be quantized [33]. For example, (i) because of the fact that all matter fields are quantized the interactions, generated by theses fields, must also be quantized. (ii) In quantum mechanics and General Relativity the notion of time is completely different. (iii) Generally, in General Relativity singularities necessarily appear where physical laws are not valid anymore. -
It Is a Great Pleasure to Write This Letter on Behalf of Dr. Maria
Rigorous Quantum-Classical Path Integral Formulation of Real-Time Dynamics Nancy Makri Departments of Chemistry and Physics University of Illinois The path integral formulation of time-dependent quantum mechanics provides the ideal framework for rigorous quantum-classical or quantum-semiclassical treatments, as the spatially localized, trajectory-like nature of the quantum paths circumvents the need for mean-field-type assumptions. However, the number of system paths grows exponentially with the number of propagation steps. In addition, each path of the quantum system generally gives rise to a distinct classical solvent trajectory. This exponential proliferation of trajectories with propagation time is the quantum-classical manifestation of nonlocality. A rigorous real-time quantum-classical path integral (QCPI) methodology has been developed, which converges to the stationary phase limit of the full path integral with respect to the degrees of freedom comprising the system’s environment. The starting point is the identification of two components in the effects induced on a quantum system by a polyatomic environment. The first, “classical decoherence mechanism” is associated with phonon absorption and induced emission and is dominant at high temperature. Within the QCPI framework, the memory associated with classical decoherence is removable. A second, nonlocal in time, “quantum decoherence process”, which is associated with spontaneous phonon emission, becomes important at low temperatures and is responsible for detailed balance. The QCPI methodology takes advantage of the memory-free nature of system-independent solvent trajectories to account for all classical decoherence effects on the dynamics of the quantum system in an inexpensive fashion. Inclusion of the residual quantum decoherence is accomplished via phase factors in the path integral expression, which is amenable to large time steps and iterative decompositions. -
Arxiv:0912.2253V2 [Hep-Th] 19 Dec 2009 ‡ † ∗ Rcsi Ellratmt 1,1,1,1,15]
Uncertainty relation on world crystal and its applications to micro black holes Petr Jizba,1,2, ∗ Hagen Kleinert,1, † and Fabio Scardigli3, ‡ 1ITP, Freie Universit¨at Berlin, Arnimallee 14 D-14195 Berlin, Germany 2FNSPE, Czech Technical University in Prague, B˘rehov´a7, 115 19 Praha 1, Czech Republic 3Leung Center for Cosmology and Particle Astrophysics (LeCosPA), Department of Physics, National Taiwan University, Taipei 106, Taiwan We formulate generalized uncertainty relations in a crystal-like universe whose lattice spacing is of the order of Planck length — “world crystal”. In the particular case when energies lie near the border of the Brillouin zone, i.e., for Planckian energies, the uncertainty relation for position and momenta does not pose any lower bound on involved uncertainties. We apply our results to micro black holes physics, where we derive a new mass-temperature relation for Schwarzschild micro black holes. In contrast to standard results based on Heisenberg and stringy uncertainty relations, our mass-temperature formula predicts both a finite Hawking’s temperature and a zero rest-mass remnant at the end of the micro black hole evaporation. We also briefly mention some connections of the world crystal paradigm with ’t Hooft’s quantization and double special relativity. PACS numbers: 04.70.Dy, 03.65.-w I. INTRODUCTION tions. One may, however, investigate the consequences of taking the lattice no longer as a mere computational Recent advances in gravitational and quantum physics device, but as a bona-fide discrete network, whose links indicate that in order to reconcile the two fields with define the only possible propagation directions for sig- each other, a dramatic conceptual shift is required in nals carrying the interactions between fields sitting on our understanding of spacetime. -
Three Duality Symmetries Between Photons and Cosmic String Loops, and Macro and Micro Black Holes
Symmetry 2015, 7, 2134-2149; doi:10.3390/sym7042134 OPEN ACCESS symmetry ISSN 2073-8994 www.mdpi.com/journal/symmetry Article Three Duality Symmetries between Photons and Cosmic String Loops, and Macro and Micro Black Holes David Jou 1;2;*, Michele Sciacca 1;3;4;* and Maria Stella Mongiovì 4;5 1 Departament de Física, Universitat Autònoma de Barcelona, Bellaterra 08193, Spain 2 Institut d’Estudis Catalans, Carme 47, Barcelona 08001, Spain 3 Dipartimento di Scienze Agrarie e Forestali, Università di Palermo, Viale delle Scienze, Palermo 90128, Italy 4 Istituto Nazionale di Alta Matematica, Roma 00185 , Italy 5 Dipartimento di Ingegneria Chimica, Gestionale, Informatica, Meccanica (DICGIM), Università di Palermo, Viale delle Scienze, Palermo 90128, Italy; E-Mail: [email protected] * Authors to whom correspondence should be addressed; E-Mails: [email protected] (D.J.); [email protected] (M.S.); Tel.: +34-93-581-1658 (D.J.); +39-091-23897084 (M.S.). Academic Editor: Sergei Odintsov Received: 22 September 2015 / Accepted: 9 November 2015 / Published: 17 November 2015 Abstract: We present a review of two thermal duality symmetries between two different kinds of systems: photons and cosmic string loops, and macro black holes and micro black holes, respectively. It also follows a third joint duality symmetry amongst them through thermal equilibrium and stability between macro black holes and photon gas, and micro black holes and string loop gas, respectively. The possible cosmological consequences of these symmetries are discussed. Keywords: photons; cosmic string loops; black holes thermodynamics; duality symmetry 1. Introduction Thermal duality relates high-energy and low-energy states of corresponding dual systems in such a way that the thermal properties of a state of one of them at some temperature T are related to the properties of a state of the other system at temperature 1=T [1–6]. -
Less Decoherence and More Coherence in Quantum Gravity, Inflationary Cosmology and Elsewhere
Less Decoherence and More Coherence in Quantum Gravity, Inflationary Cosmology and Elsewhere Elias Okon1 and Daniel Sudarsky2 1Instituto de Investigaciones Filosóficas, Universidad Nacional Autónoma de México, Mexico City, Mexico. 2Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, Mexico City, Mexico. Abstract: In [1] it is argued that, in order to confront outstanding problems in cosmol- ogy and quantum gravity, interpretational aspects of quantum theory can by bypassed because decoherence is able to resolve them. As a result, [1] concludes that our focus on conceptual and interpretational issues, while dealing with such matters in [2], is avoidable and even pernicious. Here we will defend our position by showing in detail why decoherence does not help in the resolution of foundational questions in quantum mechanics, such as the measurement problem or the emergence of classicality. 1 Introduction Since its inception, more than 90 years ago, quantum theory has been a source of heated debates in relation to interpretational and conceptual matters. The prominent exchanges between Einstein and Bohr are excellent examples in that regard. An avoid- ance of such issues is often justified by the enormous success the theory has enjoyed in applications, ranging from particle physics to condensed matter. However, as people like John S. Bell showed [3], such a pragmatic attitude is not always acceptable. In [2] we argue that the standard interpretation of quantum mechanics is inadequate in cosmological contexts because it crucially depends on the existence of observers external to the studied system (or on an artificial quantum/classical cut). We claim that if the system in question is the whole universe, such observers are nowhere to be found, so we conclude that, in order to legitimately apply quantum mechanics in such contexts, an observer independent interpretation of the theory is required. -
Semi-Classical Lindblad Master Equation for Spin Dynamics
Journal of Physics A: Mathematical and Theoretical J. Phys. A: Math. Theor. 54 (2021) 235201 (13pp) https://doi.org/10.1088/1751-8121/abf79b Semi-classical Lindblad master equation for spin dynamics Jonathan Dubois∗ ,UlfSaalmann and Jan M Rost Max Planck Institute for the Physics of Complex Systems, Nöthnitzer Straße 38, 01187 Dresden, Germany E-mail: [email protected], [email protected] and [email protected] Received 25 January 2021, revised 18 March 2021 Accepted for publication 13 April 2021 Published 7 May 2021 Abstract We derive the semi-classical Lindblad master equation in phase space for both canonical and non-canonicalPoisson brackets using the Wigner–Moyal formal- ism and the Moyal star-product. The semi-classical limit for canonical dynam- ical variables, i.e. canonical Poisson brackets, is the Fokker–Planck equation, as derived before. We generalize this limit and show that it holds also for non- canonical Poisson brackets. Examples are gyro-Poisson brackets, which occur in spin ensembles, systems of recent interest in atomic physics and quantum optics. We show that the equations of motion for the collective spin variables are given by the Bloch equations of nuclear magnetization with relaxation. The Bloch and relaxation vectors are expressed in terms of the microscopic operators: the Hamiltonian and the Lindblad functions in the Wigner–Moyal formalism. Keywords: Lindblad master equations,non-canonicalvariables,Hamiltonian systems, spin systems, classical and semi-classical limit, thermodynamical limit (Some fgures may appear in colour only in the online journal) 1. Lindblad quantum master equation Since perfect isolation of a system is an idealization [1, 2], open microscopic systems, which interact with an environment, are prevalent in nature as well as in experiments. -
The Master Equation
The Master Equation Johanne Hizanidis November 2002 Contents 1 Stochastic Processes 1 1.1 Why and how do stochastic processes enter into physics? . 1 1.2 Brownian Motion: a stochastic process . 2 2 Markov processes 2 2.1 The conditional probability . 2 2.2 Markov property . 2 3 The Chapman-Kolmogorov (C-K) equation 3 3.1 The C-K equation for stationary and homogeneous processes . 3 4 The Master equation 4 4.1 Derivation of the Master equation from the C-K equation . 4 4.2 Detailed balance . 5 5 The mean-field equation 5 6 One-step processes: examples 7 6.1 The Poisson process . 8 6.2 The decay process . 8 6.3 A Chemical reaction . 9 A Appendix 11 1 STOCHASTIC PROCESSES 1 Stochastic Processes A stochastic process is the time evolution of a stochastic variable. So if Y is the stochastic variable, the stochastic process is Y (t). A stochastic variable is defined by specifying the set of possible values called 'range' or 'set of states' and the probability distribution over this set. The set can be discrete (e.g. number of molecules of a component in a reacting mixture),continuous (e.g. the velocity of a Brownian particle) or multidimensional. In the latter case, the stochastic variable is a vector (e.g. the three velocity components of a Brownian particle). The figure below helps to get a more intuitive idea of a (discrete) stochastic process. At successive times, the most probable values of Y have been drawn as heavy dots. We may select a most probable trajectory from such a picture. -
A Numerical Study of Quantum Decoherence 1 Introduction
Commun. Comput. Phys. Vol. 12, No. 1, pp. 85-108 doi: 10.4208/cicp.011010.010611a July 2012 A Numerical Study of Quantum Decoherence 1 2, Riccardo Adami and Claudia Negulescu ∗ 1 Dipartimento di Matematica e Applicazioni, Universit`adi Milano Bicocca, via R. Cozzi, 53 20125 Milano, Italy. 2 CMI/LATP (UMR 6632), Universit´ede Provence, 39, rue Joliot Curie, 13453 Marseille Cedex 13, France. Received 1 October 2010; Accepted (in revised version) 1 June 2011 Communicated by Kazuo Aoki Available online 19 January 2012 Abstract. The present paper provides a numerical investigation of the decoherence ef- fect induced on a quantum heavy particle by the scattering with a light one. The time dependent two-particle Schr¨odinger equation is solved by means of a time-splitting method. The damping undergone by the non-diagonal terms of the heavy particle density matrix is estimated numerically, as well as the error in the Joos-Zeh approxi- mation formula. AMS subject classifications: 35Q40, 35Q41, 65M06, 65Z05, 70F05 Key words: Quantum mechanics, Schr¨odinger equation, heavy-light particle scattering, interfer- ence, decoherence, numerical discretization, numerical analysis, splitting scheme. 1 Introduction Quantum decoherence is nowadays considered as the key concept in the description of the transition from the quantum to the classical world (see e.g. [6, 7, 9, 19, 20, 22, 24]). As it is well-known, the axioms of quantum mechanics allow superposition states, namely, normalized sums of admissible wave functions are once more admissible wave functions. It is then possible to construct non-localized states that lack a classical inter- pretation, for instance, by summing two states localized far apart from each other.