共查询到20条相似文献,搜索用时 62 毫秒
1.
The possibility of a frame-induced violation of Lorentz invariance due to non-inertial spin-1/2 particle motion is explored
in detail for muon decay while in orbit near the event horizon of a microscopic Kerr black hole. It is explicitly shown that
kinematic and curvature contributions to the muon’s decay spectrum—in the absence of any unforeseen processes due to quantum
gravity—lead to its stabilization at the muon’s Compton wavelength scale. This example is emblematic of the search for unambiguous
indicators to critically assess current and future approaches to quantum gravity research. 相似文献
2.
Wave packet broadening in usual quantum mechanics is a consequence of dispersion behavior of the medium which the wave propagates
in it. In this paper, we consider the problem of wave packet broadening in the framework of Generalized Uncertainty Principle(GUP)
of quantum gravity. New dispersion relations are derived in the context of GUP and it has been shown that there exists a gravitational
induced dispersion which leads to more broadening of the wave packets. As a result of these dispersion relations, a generalized
Klein-Gordon equation is obtained and its interpretation is given. 相似文献
3.
In this paper we point out some possible links between different approaches to quantum gravity and theories of the Planck scale physics. In particular, connections between loop quantum gravity, causal dynamical triangulations, Ho?ava–Lifshitz gravity, asymptotic safety scenario, Quantum Graphity, deformations of relativistic symmetries and nonlinear phase space models are discussed. The main focus is on quantum deformations of the Hypersurface Deformations Algebra and Poincaré algebra, nonlinear structure of phase space, the running dimension of spacetime and nontrivial phase diagram of quantum gravity. We present an attempt to arrange the observed relations in the form of a graph, highlighting different aspects of quantum gravity. The analysis is performed in the spirit of a mind map, which represents the architectural approach to the studied theory, being a natural way to describe the properties of a complex system. We hope that the constructed graphs (maps) will turn out to be helpful in uncovering the global picture of quantum gravity as a particular complex system and serve as a useful guide for the researchers. 相似文献
4.
The quantum discrete kinetic equations are solved to study the propagation of plane waves in a system of composite particles
with hard-sphere interactions and the filling factor (ν) being 1/2. We compare the dispersion relations thus obtained by the
relevant Pauli-blocking parameter B which describes the different-statistics particles for the quantum analog of the discrete Boltzmann system when B is positive (Bose gases), zero (Boltzmann gases), and negative (Fermi Gases). We found, as the effective magnetic field being
zero (ν = 1/2 using the composite fermion formulation), the electric field effect will induce anomalous dispersion relations. 相似文献
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7.
R. Brustein 《Fortschritte der Physik》2014,62(3):255-265
It is argued that the blackhole information paradox originates from treating the blackhole geometry as strictly classical. It is further argued that the theory of quantum fields in a classical curved space with a horizon is an ill posed problem. If the geometry is allowed to fluctuate quantum mechanically, then the horizon effectively disappears. The sharp horizon emerges only in the classical limit when the ratio of the Compton wavelength of the black hole to its Schwarzschild radius vanishes. The region of strong gravity that develops when matter collapses to form the blackhole remains visible to the whole of spacetime and has to be described by a microscopic theory of strong gravity. The arguments imply that the information paradox is demoted from a paradox involving fundamental principles of physics to the problem of describing how matter at the highest densities gravitates. 相似文献
8.
Yunxin Ye Tiberiu Harko Shi-Dong Liang 《The European Physical Journal C - Particles and Fields》2018,78(7):587
The non-commutativity of the space-time had important implications for the very early Universe, when its size was of the order of the Planck length. An important implication of this effect is the deformation of the standard dispersion relation of special relativity. Moreover, in the Planck regime gravity itself must be described by a quantum theory. We consider the implications of the modified dispersion relations for a photon gas, filling the early Universe, in the framework of loop quantum cosmology, a theoretical approach to quantum gravity. We consider three types of deformations of the dispersion relations of the photon gas, from which we obtain the Planck scale corrections to the energy density and pressure. The cosmological implications of the modified equations of state are explored in detail for all radiation models in the framework of the modified Friedmann equation of loop quantum cosmology. By numerically integrating the evolution equations we investigate the evolution of the basic cosmological parameters (scale factor, Hubble function, radiation temperature, and deceleration parameter) for a deformed photon gas filled Universe. In all models the evolution of the Universe shows the presence of a (nonsingular) bounce, corresponding to the transition from a contracting to an expanding phase. 相似文献
9.
B. G. Sidharth 《Foundations of Physics Letters》2002,15(6):577-583
Though the Planck scale is encountered in quantum super-string theory and quantum gravity, it is the Compton scale of elementary
particles that is encountered in the physical world. An explanation for this is given in terms of Brownian processes and the
duality relation. 相似文献
10.
The existence of a fundamental ultraviolet scale, such as the Planck scale, may lead to modifications of the dispersion relations for particles at high energies in some scenarios of quantum gravity. We apply effective field theory to this problem and identify dimension-5 operators that do not mix with dimensions 3 and 4 and lead to cubic modifications of dispersion relations for scalars, fermions, and vector particles. Further we show that, for electrons, photons and light quarks, clock comparison experiments bound these operators at 10(-5)/M(Pl). 相似文献
11.
Salvatore Capozziello Gerardo Cristofano Mariafelicia De Laurentis 《The European Physical Journal C - Particles and Fields》2010,69(1-2):293-303
The characteristic sizes of astrophysical structures, up to the whole observed Universe, can be recovered, in principle, assuming that gravity is the overall interaction assembling systems starting from microscopic scales, whose order of magnitude is ruled by the Planck length and the related Compton wavelength. This result agrees with the absence of screening mechanisms for the gravitational interaction and could be connected to the presence of Yukawa corrections in the Newtonian potential which introduce typical interaction lengths. This result directly comes out from quantization of primordial black holes and then characteristic interaction lengths directly emerge from quantum field theory. 相似文献
12.
Abhay Ashtekar 《General Relativity and Gravitation》2009,41(9):1927-1943
There is a precise sense in which the requirement of background independence suffices to uniquely select the kinematics of
loop quantum gravity (LQG). Specifically, the fundamental kinematic algebra of LQG admits a unique diffeomorphism invariant state. Although this result has been established rigorously, it comes as a surprise to researchers
working with other approaches to quantum gravity. The goal of this article is to explain the underlying reasons in a pedagogical
fashion using geometrodynamics, keeping the technicalities at their minimum. This discussion will bring out the surprisingly
powerful role played by diffeomorphism invariance (and covariance) in non-perturbative, canonical quantum gravity. 相似文献
13.
P. Narayana Swamy 《International Journal of Theoretical Physics》2009,48(8):2432-2440
Many of us are familiar with Feynman’s “proof” of 1948, as revealed by Dyson, which demonstrates that Maxwell equations of
electromagnetism are a consequence of Newton’s laws of motion of classical mechanics and the commutation relations of coordinate
and momentum of quantum mechanics. It was Feynman’s purpose to explore the universality of dynamics of particles while making
the fewest assumptions. We re-examine this formulation in the context of quantum gravity and show how Feynman’s derivation
can be extended to include quantum gravity. 相似文献
14.
Richard J. Szabo 《General Relativity and Gravitation》2010,42(1):1-29
A pedagogical introduction to some of the main ideas and results of field theories on quantized spacetimes is presented, with
emphasis on what such field theories may teach us about the problem of quantizing gravity. We examine to what extent noncommutative
gauge theories may be regarded as gauge theories of gravity. UV/IR mixing is explained in detail and we describe its relations
to renormalization, to gravitational dynamics, and to deformed dispersion relations in models of quantum spacetime of interest
in string theory and in doubly special relativity. We also discuss some potential experimental probes of spacetime noncommutativity. 相似文献
15.
Differential geometric formulation of quantum gauge theory of gravity is studied in this paper. The quantumgauge theory of gravity is formulated completely in the framework of traditional quantum field theory. In order to studythe relationship between quantum gauge theory of gravity and traditional quantum gravity which is formulated in curvedspace, it is important to set up the geometry picture of quantum gauge theory of gravity. The correspondence betweenquantum gauge theory of gravity and differential geometry is discussed and the geometry picture of quantum gaugetheory of gravity is studied. 相似文献
16.
Lattice waves including a longitudinal wave and a transverse wave in two-dimensional hexagonal quantum plasma crystals are investigated by using the modified Debye-Hückel screening potential. It is shown that there exists an unstable region of lattice parameters, where the system will melt. The general dispersion relations are derived, and the waves propagating parallel to a primitive translation vector are discussed. We find that both the longitudinal and transverse waves are acoustic-like, and the longitudinal wave has a greater sound speed than that of the transverse wave in the long wavelength limit region. 相似文献
17.
On the kinematics of the torsion of space-time 总被引:1,自引:0,他引:1
Friedrich W. Hehl 《Foundations of Physics》1985,15(4):451-471
On a macroscopic level we take general relativity as the appropriate theory of space-time and gravity. We will argue that, on a more microscopic level, in the Compton wavelength regime of elementary particles, there are good reasons for suspecting the presence of a torsion of space-time. A corresponding gaugetheoretical formalism related to the Poincaré group is reviewed, and the kinematical consequences of the presence of a torsion are worked out. In particular we discuss the operational meaning and the measurability of torsion. The dynamics of torsion is left for a forthcoming article. 相似文献
18.
Recently proposed two swampland criteria that arising from string theory landscape leads to the important challenge of the realization of single-field inflationary models. Especially one of swampland criteria which implies a large tensor-to-scalar ratio is strongly in tension with recent observational results. In this paper, we explore the possibility the swampland conjectures could be compatible with single-field inflationary scenarios if the effects due to the quantum theory of gravity are considered. We show that the quantum gravitational effects due to the nonlinear dispersion relation provides significant modifications on the amplitude of both the scalar and tensor perturbation spectra. Such modifications could be either raise or reduce the perturbation spectra depending on the values of the parameters in the nonlinear terms of the dispersion relations. Therefore, these effects can reduce the tensor-to-scalar ratio to a smaller value, which helps to relax the tension between the swampland conjecture and observational data. 相似文献
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Sudhaker Upadhyay 《Annals of Physics》2014,340(1):110-118
In this paper we discuss the absolutely anticommuting nilpotent symmetries for perturbative quantum gravity in general curved spacetime in linear and non-linear gauges. Further, we analyze the finite field-dependent BRST (FFBRST) transformation for perturbative quantum gravity in general curved spacetime. The FFBRST transformation changes the gauge-fixing and ghost parts of the perturbative quantum gravity within functional integration. However, the operation of such symmetry transformation on the generating functional of perturbative quantum gravity does not affect the theory on physical ground. The FFBRST transformation with appropriate choices of finite BRST parameter connects non-linear Curci–Ferrari and Landau gauges of perturbative quantum gravity. The validity of the results is also established at quantum level using Batalin–Vilkovisky (BV) formulation. 相似文献