scholarly journals Inflaton and metric fluctuations in the early universe from a 5D vacuum state

2006 ◽  
Vol 635 (5-6) ◽  
pp. 243-246 ◽  
Author(s):  
Agustin Membiela ◽  
Mauricio Bellini
2017 ◽  
Vol 26 (12) ◽  
pp. 1743006 ◽  
Author(s):  
Elliot Nelson ◽  
C. Jess Riedel

We argue that preferred classical variables emerge from the entanglement structure of a pure quantum state in the form of redundant records: information shared between many subsystems. Focusing on the early universe, we ask how classical metric perturbations emerge from vacuum fluctuations in an inflationary background. We show that the squeezing of the quantum state for super-horizon modes, along with minimal gravitational interactions, leads to decoherence and to an exponential number of records of metric fluctuations on very large scales, [Formula: see text], where [Formula: see text] is the amplitude of metric fluctuations. This determines a preferred decomposition of the inflationary wavefunction into orthogonal “branches” corresponding to classical metric perturbations, which defines an inflationary entropy production rate and accounts for the emergence of stochastic, inhomogeneous spacetime geometry.


2020 ◽  
Vol 2020 (12) ◽  
Author(s):  
Sujoy K. Modak

Abstract We report the existence of an Unruh like effect, for physical observers (cosmo- logical and comoving observers) in the radiation dominated early universe, which is possible due to the discovery of a new vacuum state (referred here as the T−vacuum). Both the comoving and the cosmological observers, who are crucial in our understanding of cosmology, observe this T−vacuum as a particle excited state and are able to detect radiation due to particle creation. We draw a robust analogy with the Unruh effect, whereby — (i) the physical observers here are closely analogous to the accelerated (Rindler) observers in the flat spacetime, and (ii) the T−vacuum plays the role of the Minkowski vacuum state which contains particles when viewed from the physical observers frame. Our analogy is further supported by a proof of well-defined (hadamard) behavior of the T−vacuum in the entire spacetime. All our analysis of the particle creation process is done here within a two dimensional set up.


2005 ◽  
Vol 20 (19) ◽  
pp. 4683-4689 ◽  
Author(s):  
J. W. MOFFAT

A mechanism for suppressing the cosmological constant is described, using a superconducting analogy in which fermions coupled perturbatively to gravitons are in an unstable false vacuum. The coupling of the fermions to gravitons and a screened attractive interaction among pairs of fermions generates fermion condensates with zero momentum and a phase transition induces a non-perturbative transition to a true vacuum state. This produces a positive energy gap Δ in the vacuum energy identified with [Formula: see text] where Λ is the cosmological constant. In the strong coupling limit, a large cosmological constant induces a period of inflation in the early universe, followed by a weak coupling limit in which [Formula: see text] vanishes exponentially fast as the universe expands due to the dependence of the energy gap on the density of Fermi surface fermions, predicting a small cosmological constant in the early universe.


Author(s):  
Iryna Dobronravova

The cosmological conception of the Multiverse was formulated based on unitary gauge theories in the Physics of high energy. Theoretically expected, the quantum fluctuations of the original scalar field in a vacuum state and different variants of local symmetries breaking in the process of Early Universe expansion were the reasons for the cosmological idea of many possible worlds or Multiverse. Together with the inflationary cosmological model, these ideas successfully solved the problems of Big Bang theory with an explanation of observable quasi-Euclidean geometry in our world and isotropy and homogeneity of space on a mega-scale. New observational data, especially discovery of accelerative widening of space, so as the problem of dark matter and dark energy put for cosmology the new questions. These questions need to be philosophically comprehended. Professor Sergiy Krymsky offered an interesting understanding of the notion of "matter" in the situation of many worlds in the 80s. He considered each of the possible worlds as "matter, kept in its specificity", which existed in its own space and time with its set of elements, physical laws and constants. However, his considering the original vacuum state of scalar field as non-being is not satisfied because its heterogeneity defines further places for becoming of Galaxies. In this article, the author considers the ideas about the ontological status of the original state of the Early Universe in modern cosmological Multiverse theories and discusses the possible antinomies in these transcendental ideas and their difference from Kantian ones. Experience of solution the Kant’s antinomy in history of physics was taken into account. It was the second antinomy of discreetness / continuality. The solution was haven get in a way proposed by Kant, namely with empirical research and their theoretical explanations. Cosmological application of High Energy Physics gets it to transcendental ideas area, namely to the problem of our world becoming one of the possible worlds, just as a particular variant of first Kant's antinomy. However, formulation of antinomy connected with consideration of the ontological status of original state for becoming of our world has other categorical expressions than Kantian one. The front position belongs here to categories of possibility and actuality, which Kant did not include in the area of transcendental ideas, thinking that the contingency, connecting with possibility, must be changed by inevitable necessity in cognitive progress. On the contrary, contingency has the main place in modern cosmological scenarios, depending on multiple possibilities. So categories of possibility and actuality in the foundations of scientific theories need special attention. Now it touches upon at least two moments: the virtual particles as abstract objects of relativistic quantum theories and to the problem of understanding the ontological status of category "matter" in foundations of many world cosmology in the context of relations to categories "possibility", "actuality" and "reality".


1989 ◽  
Vol 159 (10) ◽  
pp. 393
Author(s):  
Ya.A. Smorodinskii
Keyword(s):  

2011 ◽  
Vol 193 (1) ◽  
pp. 7 ◽  
Author(s):  
Carla M. Coppola ◽  
Savino Longo ◽  
Mario Capitelli ◽  
Francesco Palla ◽  
Daniele Galli

1998 ◽  
Vol 13 (05) ◽  
pp. 347-351 ◽  
Author(s):  
MURAT ÖZER

We attempt to treat the very early Universe according to quantum mechanics. Identifying the scale factor of the Universe with the width of the wave packet associated with it, we show that there cannot be an initial singularity and that the Universe expands. Invoking the correspondence principle, we obtain the scale factor of the Universe and demonstrate that the causality problem of the standard model is solved.


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