scholarly journals Notes on nonlocal projective measurements in relativistic systems

2014 ◽  
Vol 351 ◽  
pp. 773-786 ◽  
Author(s):  
Shih-Yuin Lin
2012 ◽  
Vol 86 (12) ◽  
Author(s):  
Jonathan Seyrich ◽  
Georgios Lukes-Gerakopoulos
Keyword(s):  

1987 ◽  
Vol 1 (1) ◽  
pp. 56-68
Author(s):  
Christian Günther

Galilei's fundamental principle is reformulated in terms of abstract geometry and it is generalized to nonlinear and relativistic systems. As a consequence the notion of a general mechanical system is developed and shown to be a universal frame for particle dynamics.


1982 ◽  
Vol 14 (8) ◽  
pp. 731-740 ◽  
Author(s):  
Peter G. Bergmann ◽  
Arthur Komar

Quantum ◽  
2019 ◽  
Vol 3 ◽  
pp. 117 ◽  
Author(s):  
Abel Molina

Performing perfect/conclusive quantum state exclusion means to be able to discard with certainty at least one out ofnpossible quantum state preparations by performing a measurement of the resulting state. This task of state exclusion has recently been studied at length in \cite{bandyopadhyay2014conclusive}, and it is at the heart of the celebrated PBR thought experiment \cite{pusey2012reality}. When all the preparations correspond to pure states and there are no more of them than their common dimension, it is an open problem whether POVMs give any additional power for this task with respect to projective measurements. This is the case even for the simple case of three states in three dimensions, which is mentioned in \cite{caves2002conditions} as unsuccessfully tackled. In this paper, we give an analytical proof that in this case considering POVMs does indeed not give any additional power with respect to projective measurements. To do so, we first make without loss of generality some assumptions about the structure of an optimal POVM. The justification of these assumptions involves arguments based on convexity, rank and symmetry properties. We show then that any pure states perfectly excluded by such a POVM meet the conditions identified in \cite{caves2002conditions} for perfect exclusion by a projective measurement of three pure states in three dimensions. We also discuss possible generalizations of our work, including an application of Quadratically Constrained Quadratic Programming that might be of special interest.


2021 ◽  
Vol 3 (4) ◽  
Author(s):  
Niraj Kumar ◽  
Ulysse Chabaud ◽  
Elham Kashefi ◽  
Damian Markham ◽  
Eleni Diamanti

2020 ◽  
Author(s):  
Mark Zilberman

The hypothetical “Dimming Effect” describes the change of the number of photons arriving from a moving light source per unit of time. In non-relativistic systems, the “Dimming effect” may occur due to the growing distance of light sources moving away from the receiver. This means that due to the growing distance, the photons continuously require more time to reach the receiver, which reduces the number of received photons per time unit compared to the number of emitted photons. Understandably, the proposed “Dimming effect” must be tested (confirmed or rejected) through observations. a. This article provides the formula for the calculation of “Dimming effect” values using the redshift parameter Z widely used in astronomy. b. The “Dimming effect” can possibly be detected utilizing the orbital movement of the Earth around the Sun. In accordance to the “Dimming effect”, observers on Earth will view 1.0001 more photons per time unit emitted by stars located near the ecliptic plane in the direction of the Earth orbiting the Sun. And, in contrast, observers will view only 0.9999 photons per time unit emitted by stars located near the ecliptic plane in the direction opposite to the Earth orbiting the Sun. Calculating precise measurements of the same stars within a 6-month period can possibly detect this difference. These changes in brightness are not only for specific stars, as the change in brightness takes place for all stars near the ecliptic in the direction of the Earth’s orbit around the Sun and in the opposite direction. c. The “Dimming effect” can possibly be detected in a physics laboratory using a moving light source (or mirror) and photon counters located in the direction of travel and in the opposite direction. d. In theory, Dilation of time can also be used for testing the existence of the “Dimming effect.” However, in experiments on Earth this effect appears in only the 14th digit after the decimal point and testing does not appear to be feasible. e. Why is it important to test the “Dimming effect?” If confirmed, it would allow astronomers to adjust values of "Standard Candles" used in astronomy. Since “Standard Candles” are critical in various cosmological models, the “Dimming effect” can correct models and/or reveal and support new models. If it is proved that the “Dimming effect” does not exist, it will mean that the number of photons arriving per unit of time does not depend on the speed of the light source and observer, which is not so apparent.


2018 ◽  
Vol 93 (6) ◽  
pp. 064001 ◽  
Author(s):  
L Magazzù ◽  
J D Jaramillo ◽  
P Talkner ◽  
P Hänggi

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