scholarly journals Space-Time Quantum Imaging

Entropy ◽  
2015 ◽  
Vol 17 (3) ◽  
pp. 1508-1534 ◽  
Author(s):  
Ronald Meyers ◽  
Keith Deacon
2013 ◽  
Author(s):  
Ronald E. Meyers ◽  
Keith S. Deacon ◽  
Arnold Tunick

2013 ◽  
Author(s):  
Ronald E. Meyers ◽  
Keith S. Deacon ◽  
Arnold Tunick

Universe ◽  
2021 ◽  
Vol 7 (6) ◽  
pp. 189
Author(s):  
Diego A. R. Dalvit ◽  
Wilton J. M. Kort-Kamp

Temporal modulation of the quantum vacuum through fast motion of a neutral body or fast changes of its optical properties is known to promote virtual into real photons, the so-called dynamical Casimir effect. Empowering modulation protocols with spatial control could enable the shaping of spectral, spatial, spin, and entanglement properties of the emitted photon pairs. Space–time quantum metasurfaces have been proposed as a platform to realize this physics via modulation of their optical properties. Here, we report the mechanical analog of this phenomenon by considering systems in which the lattice structure undergoes modulation in space and in time. We develop a microscopic theory that applies both to moving mirrors with a modulated surface profile and atomic array meta-mirrors with perturbed lattice configuration. Spatiotemporal modulation enables motion-induced generation of co- and cross-polarized photon pairs that feature frequency-linear momentum entanglement as well as vortex photon pairs featuring frequency-angular momentum entanglement. The proposed space–time dynamical Casimir effect can be interpreted as induced dynamical asymmetry in the quantum vacuum.


A momentum space formulation of curved space–time quantum field theory is presented. Such a formulation allows the riches of momentum space calculational techniques already existing in nuclear physics to be exploited in the application of quantum field theory to cosmology and astrophysics. It is demonstrated that one such technique can allow exact, or very accu­rate approximate, results to be obtained in cases which are intractable in coordinate space. An efficient method of numerical solution is also described.


2002 ◽  
Vol 528 (3-4) ◽  
pp. 181-187 ◽  
Author(s):  
Giovanni Amelino-Camelia
Keyword(s):  

Author(s):  
Maciej Gos

The general theory of relativity and field theory of matter generate an interesting ontology of space-time and, generally, of nature. It is a monistic, anti-atomistic and geometrized ontology — in which the substance is the metric field — to which all physical events are reducible. Such ontology refers to the Cartesian definition of corporeality and to Plato's ontology of nature presented in the Timaeus. This ontology provides a solution to the dispute between Clark and Leibniz on the issue of the ontological independence of space-time from distribution of events. However, mathematical models of space-time in physics do not solve the problem of the difference between time and space dimensions (invariance of equations with regard to the inversion of time arrow). Recent research on space-time singularities and asymmetrical in time quantum theory of gravitation will perhaps allow for the solution of this problem based on the structure of space-time and not merely on thermodynamics.


Author(s):  
R. C. Pooser ◽  
B. J. Lawrie ◽  
D. D. Earl ◽  
T. S. Humble ◽  
J. Schaake

2003 ◽  
Vol 18 (33n35) ◽  
pp. 2525-2532 ◽  
Author(s):  
ALESSANDRO TORRIELLI

We improve the study of the lack of perturbative unitarity of noncommutative space-time quantum field theories derived from open string theory in electric backgrounds, enforcing the universality of the mechanism by which a tachyonic branch cut appears when the Seiberg-Witten limit freezes the string in an unstable vacuum. The main example is realized in the context of the on-shell four-tachyon amplitude of the bosonic string, and the dependence of the phenomenon on the brane-worldvolume dimension is analysed. We discuss the possibility of a proof in superstring theory, and finally mention the NCOS limit in this framework.


2010 ◽  
Vol 21 (11) ◽  
pp. 1329-1340 ◽  
Author(s):  
SAURO SUCCI

Based on a formal analogy between space-time quantum fluctuations and classical Kolmogorov fluid turbulence, we suggest that the dynamic growth of the Universe from Planckian to macroscopic scales should be characterized by the presence of a fluctuating volume-flux (FVF) invariant. The existence of such an invariant could be tested in numerical simulations of quantum gravity, and may also stimulate the development of a new class of hierarchical models of quantum foam, similar to those currently employed in modern phenomenological research on fluid turbulence. The use of such models shows that the simple analogy with Kolmogorov turbulence is not compatible with a fine-scale fractal structure of quantum space-time. Hence, should such theories prove correct, they would imply that the scaling properties of quantum fluctuations of space-time are subtler than those described by the simple Kolmogorov analogy.


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