Issue |
EPL
Volume 139, Number 4, August 2022
|
|
---|---|---|
Article Number | 49002 | |
Number of page(s) | 5 | |
Section | Gravitation, cosmology and astrophysics | |
DOI | https://doi.org/10.1209/0295-5075/ac83ea | |
Published online | 09 August 2022 |
Implications of a holographic density of states on inflation
Department of Physics & Astronomy, Rutgers, The State University of New Jersey - 136 Frelinghuysen Road, Piscataway, NJ 08854-8019, USA
(a) ramakrishna@physics.rutgers.edu (corresponding author)
Received: 8 February 2022
Accepted: 25 July 2022
There is theoretical evidence that the number of degrees of freedom in quantum fields decreases as one studies them at extremely short distances. This emerges from the study of entropy of black holes, as well as from holographic theories in AdS geometries. Presumably a theory of quantum gravity will provide an explicit description of how the number of degrees of freedom thin out as one studies high energy scales. We do not have a comprehensive theory of how such a thinning of degrees of freedom would occur. It is likely that there might be residual (and measurable) effects at larger length scales, though this might be significant only near the Planck scale. There are very few instances in Nature where one might be able to see effects of this thinning. One promising venue is in the phenomenon of inflation, produced in the simplest models through a scalar inflaton field in a potential with a flat (“slow-roll”) part as well as a potential well. During inflation, fluctuations of small length scales are stretched to large scales and then exit the Hubble horizon. We compute the effect of such a thinning of degrees of freedom upon the running of the spectral index of quantum fluctuations of the inflaton and deduce that this will lead to a small positive power of wave vector (opposite to the usual , i.e., negative power correction). Some comments are then made about the impact on observations (or non-observations) of such fluctuations (Martin J. and Ringeval C., Phys. Rev. D, 69 (2004) 083515).
© 2022 The author(s)
Published by the EPLA under the terms of the Creative Commons Attribution 4.0 International License (CC-BY). Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.