scholarly journals Thermal Quantum Spacetime

Universe ◽  
2019 ◽  
Vol 5 (8) ◽  
pp. 187 ◽  
Author(s):  
Isha Kotecha
Keyword(s):  
Quantum Gravity ◽  
Statistical Mechanics ◽  
Degrees Of Freedom ◽  
Field Theories ◽  
Information Theoretic ◽  
Statistical Field ◽  
The Status ◽  
Gravity System ◽  
Shed Light ◽  
Quantum Spacetime

The intersection of thermodynamics, quantum theory and gravity has revealed many profound insights, all the while posing new puzzles. In this article, we discuss an extension of equilibrium statistical mechanics and thermodynamics potentially compatible with a key feature of general relativity, background independence; and we subsequently use it in a candidate quantum gravity system, thus providing a preliminary formulation of a thermal quantum spacetime. Specifically, we emphasise an information-theoretic characterisation of generalised Gibbs equilibrium that is shown to be particularly suited to background independent settings, and in which the status of entropy is elevated to being more fundamental than energy. We also shed light on its intimate connections with the thermal time hypothesis. Based on this, we outline a framework for statistical mechanics of quantum gravity degrees of freedom of combinatorial and algebraic type, and apply it in several examples. In particular, we provide a quantum statistical basis for the origin of covariant group field theories, shown to arise as effective statistical field theories of the underlying quanta of space in a certain class of generalised Gibbs states.

scholarly journals Renormalization of Group Field Theories for Quantum Gravity: New Computations and Some Suggestions

2021 ◽  
Vol 8 ◽  
Author(s):  
Marco Finocchiaro ◽  
Daniele Oriti
Keyword(s):  
Field Theory ◽  
Quantum Gravity ◽  
Research Area ◽  
Scaling Behavior ◽  
Field Theories ◽  
Numerical Techniques ◽  
Research Directions ◽  
The Status ◽  
Group Field Theory

We discuss motivation and goals of renormalization analyses of group field theory models of simplicial 4d quantum gravity, and review briefly the status of this research area. We present some new computations of perturbative Group field theories amplitudes, concerning in particular their scaling behavior, and the numerical techniques employed to obtain them. Finally, we suggest a number of research directions for further progress.

scholarly journals PLANCK FLUCTUATIONS, MEASUREMENT UNCERTAINTIES AND THE HOLOGRAPHIC PRINCIPLE

2007 ◽  
Vol 22 (11) ◽  
pp. 791-806 ◽  
Author(s):  
MANFRED REQUARDT
Keyword(s):  
Quantum Gravity ◽  
Statistical Mechanics ◽  
Critical Analysis ◽  
Degrees Of Freedom ◽  
Planck Scale ◽  
Quantum Statistical Mechanics ◽  
Correlated Systems ◽  
Logical Independence ◽  
Measurement Uncertainties ◽  
Quantum Statistical

Starting from a critical analysis of recently reported surprisingly large uncertainties in length and position measurements deduced within the framework of quantum gravity, we embark on an investigation both of the correlation structure of Planck scale fluctuations and the role the holographic hypothesis is possibly playing in this context. While we prove the logical independence of the fluctuation results and the holographic hypothesis (in contrast to some recent statements in that direction) we show that by combining these two topics one can draw quite strong and interesting conclusions about the details of the fluctuation structure and the microscopic dynamics on the Planck scale. We further argue that these findings point to a possibly new and generalized form of quantum statistical mechanics of strongly (anti)correlated systems of degrees of freedom in this fundamental regime.

scholarly journals Quantum information probes of charge fractionalization in large-N gauge theories

2021 ◽  
Vol 2021 (5) ◽  
Author(s):  
Brandon S. DiNunno ◽  
Niko Jokela ◽  
Juan F. Pedraza ◽  
Arttu Pönni
Keyword(s):  
Degrees Of Freedom ◽  
Gauge Theories ◽  
Entanglement Entropy ◽  
Coarse Grained ◽  
Strongly Coupled ◽  
Information Theoretic ◽  
Large N ◽  
Wide Range ◽  
Charge Fractionalization ◽  
Electric Flux

Abstract We study in detail various information theoretic quantities with the intent of distinguishing between different charged sectors in fractionalized states of large-N gauge theories. For concreteness, we focus on a simple holographic (2 + 1)-dimensional strongly coupled electron fluid whose charged states organize themselves into fractionalized and coherent patterns at sufficiently low temperatures. However, we expect that our results are quite generic and applicable to a wide range of systems, including non-holographic. The probes we consider include the entanglement entropy, mutual information, entanglement of purification and the butterfly velocity. The latter turns out to be particularly useful, given the universal connection between momentum and charge diffusion in the vicinity of a black hole horizon. The RT surfaces used to compute the above quantities, though, are largely insensitive to the electric flux in the bulk. To address this deficiency, we propose a generalized entanglement functional that is motivated through the Iyer-Wald formalism, applied to a gravity theory coupled to a U(1) gauge field. We argue that this functional gives rise to a coarse grained measure of entanglement in the boundary theory which is obtained by tracing over (part) of the fractionalized and cohesive charge degrees of freedom. Based on the above, we construct a candidate for an entropic c-function that accounts for the existence of bulk charges. We explore some of its general properties and their significance, and discuss how it can be used to efficiently account for charged degrees of freedom across different energy scales.

scholarly journals The Swampland Conjectures: A Bridge from Quantum Gravity to Particle Physics

Universe ◽  
2021 ◽  
Vol 7 (8) ◽  
pp. 273
Author(s):  
Mariana Graña ◽  
Alvaro Herráez
Keyword(s):  
Effective Field Theories ◽  
Quantum Gravity ◽  
Particle Physics ◽  
Effective Field ◽  
Low Energy ◽  
Field Theories ◽  
Neutrino Masses ◽  
Higgs Potential ◽  
Photon Mass ◽  
Effective Theories

The swampland is the set of seemingly consistent low-energy effective field theories that cannot be consistently coupled to quantum gravity. In this review we cover some of the conjectural properties that effective theories should possess in order not to fall in the swampland, and we give an overview of their main applications to particle physics. The latter include predictions on neutrino masses, bounds on the cosmological constant, the electroweak and QCD scales, the photon mass, the Higgs potential and some insights about supersymmetry.

scholarly journals The Trials and Tribulations of Applied Triangulation: Weighing Different Data Sources

2016 ◽  
Vol 12 (2) ◽  
pp. 166-181 ◽  
Author(s):  
Florian G. Kern
Keyword(s):  
Quantitative Research ◽  
Political Power ◽  
Data Sources ◽  
Qualitative And Quantitative ◽  
Practical Research ◽  
The Status ◽  
Analytical Strategies ◽  
Depth Interviews ◽  
Shed Light ◽  
Illustrative Application

Researchers employ triangulation to increase the validity of inference in qualitative and quantitative research. Leuffen, Shikano, and Walter have presented guidance as to which strategies to use when triangulating data sources. In this article, I explore how their findings can be translated for practical research purposes. I offer an illustrative application concentrating on the political power of traditional political authorities in Uganda and Tanzania. I analyze the status quo of political power and the preferred political power of traditional leaders. To triangulate, I use three sources: (1) constitutional-legal texts, (2) the Afrobarometer survey, and (3) in-depth interviews. I shed light on possible problems and analytical strategies for triangulation in practice, with a specific focus on convergence and divergence of sources.

scholarly journals PROPOSAL OF A SECOND GENERATION OF QUANTUM-GRAVITY-MOTIVATED LORENTZ-SYMMETRY TESTS: SENSITIVITY TO EFFECTS SUPPRESSED QUADRATICALLY BY THE PLANCK SCALE

2003 ◽  
Vol 12 (09) ◽  
pp. 1633-1639 ◽  
Author(s):  
GIOVANNI AMELINO-CAMELIA
Keyword(s):  
Quantum Gravity ◽  
Second Generation ◽  
Loop Quantum Gravity ◽  
Planck Scale ◽  
Cosmic Ray ◽  
Lorentz Symmetry ◽  
Planck Length ◽  
Satisfactory Description ◽  
Symmetry Tests ◽  
Quantum Spacetime

Over the last few years the study of possible Planck-scale departures from classical Lorentz symmetry has been one of the most active areas of quantum-gravity research. We now have a satisfactory description of the fate of Lorentz symmetry in the most popular noncommutative spacetimes and several studies have been devoted to the fate of Lorentz symmetry in loop quantum gravity. Remarkably there are planned experiments with enough sensitivity to reveal these quantum-spacetime effects, if their magnitude is only linearly suppressed by the Planck length. Unfortunately, in some quantum-gravity scenarios even the strongest quantum-spacetime effects are suppressed by at least two powers of the Planck length, and many authors have argued that it would be impossible to test these quadratically-suppressed effects. I here observe that advanced cosmic-ray observatories and neutrino observatories can provide the first elements of an experimental programme testing the possibility of departures from Lorentz symmetry that are quadratically Planck-length suppressed.

MANAGERS CAN ALSO RESIST CHANGES — CAN WE DEAL WITH THIS? AN EXPLORATORY STUDY FROM JAPAN

2013 ◽  
Vol 21 (04) ◽  
pp. 447-493
Author(s):  
BALÁZS VASZKUN
Keyword(s):  
Traditional Values ◽  
Traditional Management ◽  
Japanese Firms ◽  
Work Routines ◽  
The Status ◽  
Major Reform ◽  
Mass Recruitment ◽  
Dominant Coalition ◽  
High Level ◽  
Shed Light

Japan is going through a transformation, yet it is difficult to judge which model should be chosen as a direction to go in with corporate reforms. Badly needed initiatives seeking to replace outdated managerial habits by new best practices in Japanese firms are being jeopardized by organizational members whose goal is to maintain the status quo — in terms of both political power and everyday work routines. Yet managerial habits and behaviours need to change if Japanese firms are to be entrepreneurial and innovative. According to institutionalism, blocking new initiatives is normal, and societal support is needed for major reform attempts. The focus of this paper is to shed light on how society in Japan is divided when it comes to large firms altering practices with which they have been traditionally managed. Our proposition is that complex, multi-element reform packages — having a potentially opposing dominant coalition, which is the case of Japan — ought to be implemented following a well-defined, prioritized listing of elements. After examining an attitude survey carried out in Japan, our findings revealed two clusters with a particularly high level of support for traditional management. Moreover, out of the two, one appeared to be extremely passive and resistant to any sort of change. In order to fight general resistance and reform outdated practices, our survey shows that Japan could move further towards a system compensating performance rather than seniority and giving more chance to women, discarding mass-recruitment, slow promotion whilst also maintaining the most deeply-rooted traditional values such as job security, paternalism or harmony in corporate life.

scholarly journals ENTROPY AND AREA IN LOOP QUANTUM GRAVITY

2005 ◽  
Vol 14 (12) ◽  
pp. 2301-2305
Author(s):  
JOHN SWAIN
Keyword(s):  
Black Hole ◽  
Quantum Gravity ◽  
Maximum Entropy ◽  
Degrees Of Freedom ◽  
Loop Quantum Gravity ◽  
Black Hole Entropy ◽  
Black Hole Thermodynamics ◽  
Three Dimensions ◽  
Spin Network

Black hole thermodynamics suggests that the maximum entropy that can be contained in a region of space is proportional to the area enclosing it rather than its volume. We argue that this follows naturally from loop quantum gravity and a result of Kolmogorov and Bardzin' on the the realizability of networks in three dimensions. This represents an alternative to other approaches in which some sort of correlation between field configurations helps limit the degrees of freedom within a region. It also provides an approach to thinking about black hole entropy in terms of states inside rather than on its surface. Intuitively, a spin network complicated enough to imbue a region with volume only lets that volume grow as quickly as the area bounding it.

scholarly journals Autoregressive Models of the Random fields—A Survey

2020 ◽  
pp. 1-9
Keyword(s):  
Random Fields ◽  
Linear Models ◽  
Estimation Methods ◽  
Suitable Model ◽  
Main Mode ◽  
One Dimensional ◽  
Non Linear ◽  
The Status ◽  
Ar Models ◽  
Shed Light

Autoregressive (AR) random fields are widely use to describe changes in the status of real-physical objects and implemented for analyzing linear & non-linear models. AR models are Markov processes with a higher order dependence for one-dimensional time series. Actually, various estimation methods were used in order to evaluate the autoregression parameters. Although in many applications background knowledge can often shed light on the search for a suitable model, but other applications lack this knowledge and often require the type of trial errors to choose a model. This article presents a brief survey of the literatures related to the linear and non-linear autoregression models, including several extensions of the main mode models and the models developed. The use of autoregression to describe such system requires that they be of sufficiently high orders which leads to increase the computational costs.

scholarly journals Punctuation Marks and Signs of Cessation in Qur`an: a comparative study

2020 ◽  
Vol 2 (1) ◽  
pp. 49-59
Author(s):  
Abdur-Rasheed Mahmoud-Mukadam
Keyword(s):  
Comparative Study ◽  
Usual Treatment ◽  
Holy Quran ◽  
The Status ◽  
The Holy Quran ◽  
The Subject ◽  
Contemporary Writers ◽  
The Relationship ◽  
Shed Light

The subject of punctuation in Arabic writing may be one of the topics in which there was a great deal of writing. However, the close look at this paper reveals that there are some new things that the researcher is interested in highlighting in this article. To clarify positions in the Holy Quran. And that some contemporary writers do not take into account the status of these signs and interesting situation in the appropriate places, but they refuse to take into account behind their appearance when writing Arabic became randomly writing, Based on the above, the researcher can shed light on the importance of these punctuation marks and indicate the relationship between them and the signs of the Qur`anic cessation, which does not mean the use of the first place with The existence of the connection and kinship between them; because the writing of Qur`an is descriptive, it could never be treated in the places of cessation and tone as   usual treatment of the normal writing.

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