A Larger Estimate of the Entropy of the Universe (original) (raw)
ADS
Abstract
Using recent measurements of the supermassive black hole (SMBH) mass function, we find that SMBHs are the largest contributor to the entropy of the observable universe, contributing at least an order of magnitude more entropy than previously estimated. The total entropy of the observable universe is correspondingly higher, and is S obs = 3.1+3.0 -1.7 × 10104 k. We calculate the entropy of the current cosmic event horizon to be S CEH = 2.6 ± 0.3 × 10122 k, dwarfing the entropy of its interior, S CEH int = 1.2+1.1 -0.7 × 10103 k. We make the first tentative estimate of the entropy of weakly interacting massive particle dark matter within the observable universe, S dm = 1088 ± 1 k. We highlight several caveats pertaining to these estimates and make recommendations for future work.
Publication:
The Astrophysical Journal
Pub Date:
February 2010
DOI:
arXiv:
Bibcode:
Keywords:
- black hole physics;
- cosmology: miscellaneous;
- diffusion;
- elementary particles;
- gravitation;
- neutrinos;
- Astrophysics - Cosmology and Nongalactic Astrophysics
E-Print:
ApJ. Accepted 11 Jan 2010. 10 pages and 10 figures. Colour version