The Time Machine Factory [unspeakable, speakable] on Time Travel -TM2019

Session

Teleportation, entanglement and CTCs/OTCs

Session II

8 Oct 2019, 14:10

Turin

73. Updates from the future

Prof. Seth Lloyd (MIT)

08/10/2019, 14:10

talk

The possibility of closed timelike curves in general relativity opens up the physical possibility of
time travel. This talk reviews the different quantum mechanical theories of closed timelike curves, and
discusses their various advantages and drawbacks. We will discuss whether it is possible to use closed
timelike curves to build a time machine.

28. Quantum Measurements of time

Prof. Lorenzo Maccone (Univ. degli Studi di Pavia)

08/10/2019, 14:55

talk

We propose a time-of-arrival operator in quantum mechanics by conditioning on a quantum clock. This allows us to bypass some of the problems of previous proposals, and to obtain a Hermitian time of arrival operator whose probability distribution arises from the Born rule and which has a clear physical interpretation. The same procedure can be employed to measure the "time at which some event...

11. Entangled histories, the two-state-vector and the pseudo-density formalisms: Towards a better understanding of quantum temporal correlations.

Prof. Marcin Nowakowski (Department of Theoretical Physics and Quantum Information, Gdansk University of Technology )

08/10/2019, 15:40

talk

The two-state-vector formalism, the entangled histories and the pseudo-density formalisms are attempts to better understand quantum correlations in time. These formalisms share some similarities, but they are not identical, having subtle differences in their interpretation and manipulation of quantum temporal structures [1, 2]. I will show, for instance, that they treat operators and states on...

31. Interrelations between local correlations, nonlocal correlations and causality

Dr Eliahu Cohen (Faculty of Engineering, Bar Ilan University)

08/10/2019, 16:25

talk

The set of quantum mechanical nonlocal correlations is unique and intriguing in many ways. Characterizing this set is expected to cast light on the fundamental physical principles governing quantum theory, those from which the mathematical structure of the theory arises. Recently, we have shown ([A. Carmi and E. Cohen, Sci. Adv. eaav8370 (2019)] and followup works) that this set may largely be...

29. The quantum theory of time: from formalism to experimental test

Prof. Joan A. Vaccaro (Griffith University)

08/10/2019, 17:05

talk

The violation of the discrete symmetries of charge conjugation (C), parity inversion (P), and time reversal (T) observed in high energy physics are clearly fundamental aspects of nature. A new quantum theory [1,2] has been introduced to demonstrate the possibility that the violations have large-scale physical effects. The new theory does not assume any conservation laws or equations of...

30. “Time” replaced by quantum correlations: experimental visualization.

Dr Ekaterina MOREVA (INRiM)

08/10/2019, 17:45

talk

The description of time in quantum mechanics and in particular in connection with quantum gravity and cosmology has always presented significant difficulties. One of descriptions based on Page and Wootters (PaW) mechanism which considers “time” as a quantum degree of freedom[1]. Here we give a complete review of the Page and Wootters' quantum time mechanism and provide experimental...

5. The temporally nonlocal character of the quantum computational speedup

Dr Giuseppe Castagnoli (Elsag Bailey ICT Division and Quantum information Laboratory)

08/10/2019, 18:10

talk

One says that there is a quantum computational speedup when the computation of the solution of a problem is more efficient quantumly than classically. Let us consider, as an example, the simplest case that Bob, the problem setter, hides a ball in a chest of four drawers. Alice, the problem solver, is to locate in by opening drawers (by querying the oracle: is the ball in that drawer?). While...