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Related papers: Dirac Equation and Planck-Scale Quantities

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Small violations of spacetime symmetries have recently been identified as promising Planck-scale signals. This talk reviews how such violations can arise in various approaches to quantum gravity, how the emergent low-energy effects can be…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Ralf Lehnert

With the simplest proof ever, we justify the significance of quantum-gravity in non-relativistic quantum mechanics together with the related theories and experiments. Since the de Broglie wave length is inverse proportional to the mass, it…

Quantum Physics · Physics 2020-01-08 Lajos Diósi

A fundamental spacetime scale in the universe leads to noncommutative spacetime and thence to a modified energy - momentum dispersion relation or equivalently to a modification of Lorentz symmetry as shown by the author and others. This…

General Physics · Physics 2009-01-27 Burra G. Sidharth

This article describes gravity experiments, where the outcome depends upon both the gravitational acceleration $g$ and the Planck constant $\hbar$. We focus on the work done with an elementary particle, the neutron.

High Energy Physics - Phenomenology · Physics 2012-07-13 Hartmut Abele , Helmut Leeb

The relevance of the Planck scale to a theory of quantum gravity has become a worryingly little examined assumption that goes unchallenged in the majority of research in this area. However, in all scientific honesty, the significance of…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Diego Meschini

Extending the commutator algebra of quantum $\kappa$-Poincar\'e symmetry to the whole of the phase space, and assuming that this algebra is to be covariant under action of deformed Lorentz generators, we derive the transformation properties…

High Energy Physics - Theory · Physics 2009-11-07 J. Kowalski-Glikman

We investigate the quantum motion of a neutral Dirac particle bouncing on a mirror in curved spacetime. We consider different geometries: Rindler, Kasner-Taub and Schwarzschild, and show how to solve the Dirac equation by using geometrical…

High Energy Physics - Theory · Physics 2008-11-26 Nicolas Boulanger , Fabien Buisseret , Philippe Spindel

Taking into account four universal constants, namely the Planck's constant $h$, the velocity of light $c$, the constant of gravitation $G$ and the Boltzmann's constant $k$ leads to structuring theoretical physics in terms of three theories…

High Energy Physics - Theory · Physics 2009-10-11 G. Cohen-Tannoudji

Suppose the usual description of spacetime as a 4-dimensional manifold with a Lorentzian metric breaks down at Planck energies. Can we still construct sensible theoretical models of the universe? Are they testable? Do they lead to a…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Fotini Markopoulou

We propose a form for the action of a relativistic particle subject to a positional force that is invariant under time reparametrization and therefore allows for a consistent Hamiltonian formulation of the dynamics. This approach can be…

Classical Physics · Physics 2012-10-10 S. Mignemi

As is well known, in quantum mechanics, the calculation rule of the probability that an eigen-value a_n is observed when the physical quantity A is measured for a state described by the state vector |> is P(a_n)=<|A_n><A_n|> . However, in…

General Physics · Physics 2008-08-06 T. Mei

Canonical quantum gravity provides insights into the quantum dynamics as well as quantum geometry of space-time by its implications for constraints. Loop quantum gravity in particular requires specific corrections due to its quantization…

General Relativity and Quantum Cosmology · Physics 2015-05-14 Martin Bojowald

A basic inconsistency arises when the Theory of Special Relativity meets with quantum phenomena at the Planck scale. Specifically, the Planck length is Lorentz invariant and should not be affected by a Lorentz boost. We argue that Planckian…

General Relativity and Quantum Cosmology · Physics 2013-09-30 A. Aurilia , E. spallucci

It is argued that the `problem of time' in quantum gravity necessitates a refinement of the local inertial structure of the world, demanding a replacement of the usual Minkowski line element by a 4+2n dimensional pseudo-Euclidean line…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Joy Christian

A particular framework for quantum gravity is the doubly special relativity (DSR) formalism that introduces a new observer independent scale (the Planck scale). We resort to the methods of statistical mechanics in this framework to…

High Energy Physics - Theory · Physics 2017-07-17 Mir Mehedi Faruk , Md. Muktadir Rahman

We revisit the quantum lattice gas model of a spinor quantum field theory-the smallest scale particle dynamics is partitioned into unitary collide and stream operations. The construction is covariant (on all scales down to a small length…

General Relativity and Quantum Cosmology · Physics 2015-03-19 Jeffrey Yepez

The Planck mass and the cosmological constant determine the minimum and the maximum distances in the physical universe. A relativistic theory that takes into account a fundamental distance limit $\ell$ on par with the fundamental speed…

General Relativity and Quantum Cosmology · Physics 2021-07-07 Tomi Koivisto , Luxi Zheng

We start from classical general relativity coupled to matter fields. Each configuration variable and its conjugate momentum, as also space-time points, are raised to the status of matrices [equivalently operators]. These matrices obey a…

General Relativity and Quantum Cosmology · Physics 2020-11-09 Tejinder P. Singh

The starting point of this work is the axiomatic existence of a smallest measurable interval, viz. the Planck time $t_P$, set by quantum fluctuations in the vacuum metric tensor. By the Relativity Principle, the same limit must then apply…

Astrophysics · Physics 2009-11-07 Richard Lieu

Traditionally, the Planck constant $h$ makes its debut appearance in quantum physics textbooks in the context of the blackbody radiation law and subsequently as a fundamental ingredient of the physics of the photoelectric effect and the…

History and Philosophy of Physics · Physics 2026-03-05 Kostas Glampedakis