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Related papers: Unitary time-reversal on non-orientable spacetimes

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The algebra of observables associated with a quantum field theory is invariant under the connected component of the Lorentz group and under parity reversal, but it is not invariant under time reversal. If we take general covariance…

Quantum Physics · Physics 2008-10-28 Peter Morgan

The time reversal of a completely-positive, nonequilibrium discrete-time quantum Markov evolution is derived via a suitable adjointness relation. Space-time harmonic processes are introduced for the forward and reverse-time transition…

Quantum Physics · Physics 2009-04-29 Francesco Ticozzi , Michele Pavon

It is shown that, in the framework of non-relativistic quantum mechanics, any conserved Hermitian operator (which may depend explicitly on the time) is the generator of a one-parameter group of unitary symmetries of the Hamiltonian and…

Quantum Physics · Physics 2015-10-19 G. F. Torres del Castillo , J. E. Herrera Flores

It is explained how the unification of resonance and decay phenomena into a consistent mathematical theory leads to quantum mechanical time-asymmetry. This provides the theoretical basis for a subsequent paper II in which the interpretation…

Quantum Physics · Physics 2007-05-23 A. Bohm , H. Kaldass , S. Komy

A possible model for quantum kinematics of a test particle in a curved space-time is proposed. Every reasonable neighbourhood V_e of a curved space-time can be equipped with a nonassociative binary operation called the geodesic…

High Energy Physics - Theory · Physics 2011-04-15 P. Kuusk , J. Ord

A general dynamical invariant operator for three coupled time-dependent oscillators is derived. Although the obtained invariant operator satisfies the Liouville-von Neumann equation, its mathematical formula is somewhat complicated due to…

Quantum Physics · Physics 2022-12-16 Jeong Ryeol Choi

Deriving an arrow of time from time-reversal symmetric microscopic dynamics is a fundamental open problem in many areas of physics, ranging from cosmology, to particle physics, to thermodynamics and statistical mechanics. Here we focus on…

Quantum Physics · Physics 2025-01-31 Thomas Guff , Chintalpati Umashankar Shastry , Andrea Rocco

We consider electrodynamics on a noncommutative spacetime using the enveloping algebra approach and perform a non-relativistic expansion of the effective action. We obtain the Hamiltonian for quantum mechanics formulated on a canonical…

High Energy Physics - Theory · Physics 2009-11-11 Xavier Calmet , Michele Selvaggi

An apparent paradox is resolved that concerns the existence of time operators which have been derived for the quantum harmonic oscillator. There is an apparent paradox because, although a time operator is canonically conjugate to the…

Quantum Physics · Physics 2007-05-23 Alex Granik , H. Ralph Lewis

The classical procedures which define the relativistic notion of space-time can be implemented in the framework of Quantum Field Theory. Only relying on the conformal symmetries of field propagation, time-frequency transfer and localization…

General Relativity and Quantum Cosmology · Physics 2013-02-27 Marc-Thierry Jaekel , Serge Reynaud

We exploit the reparametrization symmetry of a relativistic free particle to impose a gauge condition which upon quantization implies space-time noncommutativity. We show that there is an algebraic map from this gauge back to the standard…

High Energy Physics - Theory · Physics 2009-11-10 A. Pinzul , A. Stern

A generalised equivalence principle is put forward according to which space-time symmetries and internal quantum symmetries are indistinguishable before symmetry breaking. Based on this principle, a higher-dimensional extension of Minkowski…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Dorje C. Brody , Lane P. Hughston

We develop a Heisenberg-picture \emph{kinematical} framework in which (i) time is treated as a quantum observable, admitting both a relational POVM construction for semibounded spectra and a fully self-adjoint realization on an enlarged…

General Physics · Physics 2026-03-17 Vahid Kamali

It is first shown that the Dirac's equation in a relativistic frame could be modified to allow discrete time, in agreement to a recently published upper bound. Next, an exact self-adjoint $4\times 4$ relativistic time operator for…

Quantum Physics · Physics 2017-06-26 Sina Khorasani

The paper addresses the quantization of minisuperspace cosmological models by studying a possible solution to the problem of time and time asymmetries in quantum cosmology. Since General Relativity does not have a privileged time variable…

General Relativity and Quantum Cosmology · Physics 2009-11-07 Mario Castagnino , Gabriel Catren , Rafael Ferraro

There are enough reasons for us to consider time as a dynamical variable or operator; but according to Pauli's argument the existence of a self-adjoint time operator is incompatible with the semi-boundedness of Hamiltonian spectrum. In this…

Quantum Physics · Physics 2011-04-26 Z. Y. Wang , B. Chen , C. D. Xiong

We provide a general treatment for the temporal coupled-mode theory with arbitrary numbers of modes and ports, and derive tight bounds for the coupling phases in addition to coupling strengths under time-reversal symmetry. We report…

Applied Physics · Physics 2024-07-25 Ken X. Wang

The a priori time in conventional quantum mechanics is shown to contradict the uncertainty principle. A possible solution is given.

General Relativity and Quantum Cosmology · Physics 2007-05-23 Hitoshi Kitada

We show that whenever the symmetry group of a field theory commutes with one or more antiunitary operators $T$, which do not have to but may represent the reversal of physical time, the number of linearly independent contact two-body…

High Energy Physics - Theory · Physics 2019-12-25 Igor F. Herbut

Contrary to established beliefs, spacetime may not be time-orientable. By considering an experimental test of time orientability it is shown that a failure of time-orientability of a spacetime region would be indistinguishable from a…

General Relativity and Quantum Cosmology · Physics 2009-11-07 Mark J Hadley