Holographic Principle and the Surface of Last Scatter

TL;DR

This paper calculates the entropy of the observable universe using WMAP7 data and finds it exceeds the simplified holographic bound by a significant margin, highlighting potential limitations of the holographic principle.

Contribution

It provides a novel entropy calculation of the visible universe based on observational data, challenging simplified holographic bounds.

Findings

The universe's entropy exceeds the holographic bound by a factor of about 8.85.

The shift parameter measurement critically influences the entropy calculation.

Results suggest limitations of simplified holographic principles in cosmology.

Abstract

Using data, provided by WMAP7, I calculate the entropy of the visible universe, where visible refers to electromagnetic radiation, and hence the visible universe is bounded by the Surface of Last Scatter. The dimensionless entropy, $S/k$, is $(8.85 \pm 0.37)$ times larger than allowed by a simplified and non-covariant holographic principle, that the entropy cannot exceed that of a black hole. The measurement of a shift parameter, introduced by Bond, Efstathiou and Tegmark in 1997, plays an important role in the accuracy of the calculation, which leads to the large discrepancy.