Time-Reversal, Irreversibility and Arrow of Time in Quantum Mechanics

2006 ◽  
Vol 36 (3) ◽  
pp. 407-426 ◽  
Author(s):  
M. Castagnino ◽  
M. Gadella ◽  
O. Lombardi
Keyword(s):  
Quantum Mechanics ◽  
Time Reversal ◽  
Arrow Of Time ◽  
Time In Quantum Mechanics

The preparation-registration arrow of time in quantum mechanics

1994 ◽  
Vol 189 (6) ◽  
pp. 442-448 ◽  
Author(s):  
A. Bohm ◽  
I. Antoniou ◽  
P. Kielanowski
Keyword(s):  
Quantum Mechanics ◽  
Arrow Of Time ◽  
Time In Quantum Mechanics

scholarly journals Symmetry and the Arrow of Time in Theoretical Black Hole Astrophysics

2015 ◽  
Vol 2015 ◽  
pp. 1-5
Author(s):  
David Garofalo
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Active Galactic Nuclei ◽  
Accretion Disks ◽  
Time Reversal ◽  
Large Scale ◽  
Galactic Nuclei ◽  
Arrow Of Time ◽  
Time Symmetry ◽  
The Universe

While the basic laws of physics seem time-reversal invariant, our understanding of the apparent irreversibility of the macroscopic world is well grounded in the notion of entropy. Because astrophysics deals with the largest structures in the Universe, one expects evidence there for the most pronounced entropic arrow of time. However, in recent theoretical astrophysics work it appears possible to identify constructs with time-reversal symmetry, which is puzzling in the large-scale realm especially because it involves the engines of powerful outflows in active galactic nuclei which deal with macroscopic constituents such as accretion disks, magnetic fields, and black holes. Nonetheless, the underlying theoretical structure from which this accreting black hole framework emerges displays a time-symmetric harmonic behavior, a feature reminiscent of basic and simple laws of physics. While we may expect such behavior for classical black holes due to their simplicity, manifestations of such symmetry on the scale of galaxies, instead, surprise. In fact, we identify a parallel between the astrophysical tug-of-war between accretion disks and jets in this model and the time symmetry-breaking of a simple overdamped harmonic oscillator. The validity of these theoretical ideas in combination with this unexpected parallel suggests that black holes are more influential in astrophysics than currently recognized and that black hole astrophysics is a more fundamental discipline.

scholarly journals Relational Event-Time in Quantum Mechanics

2021 ◽  
Vol 52 (1) ◽  
Author(s):  
Sebastian Fortin ◽  
Olimpia Lombardi ◽  
Matías Pasqualini
Keyword(s):  
Quantum Mechanics ◽  
Event Time ◽  
Time In Quantum Mechanics

GALILEAN AND DISCRETE SPACE-TIME SYMMETRIES OF ROY-SINGH DETERMINISTIC QUANTUM MECHANICS

1995 ◽  
Vol 10 (32) ◽  
pp. 4641-4650
Author(s):  
ARVIND KUMAR
Keyword(s):  
Quantum Mechanics ◽  
Quantum Theory ◽  
Time Reversal ◽  
Space Time ◽  
Discrete Space ◽  
Galilean Space

The recent deterministic quantum theory of Roy and Singh is shown to be covariant with respect to Galilean, space reflection and time reversal transformations.

scholarly journals Emergence of Time in Quantum Gravity: Is Time Necessarily Flowing?

KronoScope ◽  
2013 ◽  
Vol 13 (1) ◽  
pp. 67-84 ◽  
Author(s):  
Pierre Martinetti
Keyword(s):  
Quantum Mechanics ◽  
Quantum Gravity ◽  
Proper Time ◽  
Dimensional Space ◽  
Thermal Time ◽  
List Type ◽  
State Dependent ◽  
Dimensional Space Time ◽  
Flow Of Time ◽  
Time In Quantum Mechanics

Abstract We discuss the emergence of time in quantum gravity and ask whether time is always “something that flows.” We first recall that this is indeed the case in both relativity and quantum mechanics, although in very different manners: time flows geometrically in relativity (i.e., as a flow of proper time in the four dimensional space-time), time flows abstractly in quantum mechanics (i.e., as a flow in the space of observables of the system). We then ask the same question in quantum gravity in the light of the thermal time hypothesis of Connes and Rovelli. The latter proposes to answer the question of time in quantum gravity (or at least one of its many aspects) by postulating that time is a state-dependent notion. This means that one is able to make a notion of time as an abstract flow—that we call the thermal time—emerge from the knowledge of both: the algebra of observables of the physical system under investigation; a state of thermal equilibrium of this system. Formally, the thermal time is similar to the abstract flow of time in quantum mechanics, but we show in various examples that it may have a concrete implementation either as a geometrical flow or as a geometrical flow combined with a non-geometric action. This indicates that in quantum gravity, time may well still be “something that flows” at some abstract algebraic level, but this does not necessarily imply that time is always and only “something that flows” at the geometric level.

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