January 2017 – Niayesh Afshordi

hc_cartoon-001 — Universe out of a Hologram!

Here is a new story, with a novel twist on an old story: Let’s throw out the story!

And that’s my take on Holographic Cosmology, first developed by Paul McFadden and Kostas Skenderis, as a way to understand big bang. In short we can use the properties of a quantum field theory in 3 dimensions (without time), to understand the outcome of our 3+1 dimensional big bang.

What’s new is that, working with my PhD student Beth and other collaborators, we find observational evidence for a holographic description of our Universe by analyzing the cosmic microwave background, the afterglow of the big bag. The origin of structures in the universe is one of the deepest mysteries in modern physics, and at the heart of empirical efforts to understand the big bang. It is often believed that quantum fluctuations during an early period of accelerated expansion, or cosmic inflation, have seeded these structures but the physics and origins of inflation have remained illusive. Modern advances in quantum gravity have provided strong support for a holographic conjecture, which suggests gravitational physics within a volume contains the same information as a quantum field theory on its boundary. We apply this powerful conjecture to the early universe, rewriting the observable implications of a 4-dimensional big bang, in terms of a 3-dimensional quantum field theory. Surprisingly, we discovered that some of the simplest field theories in 3 dimensions can successfully explain (nearly) all cosmological observations of the early universe. New techniques are necessary to understand the correlations in the cosmic microwave background on angles larger than 10 degrees, which is where tantalizing hints for new physics have been seen over the past 20 years.

Read our paper on Physical Review Letters or arXiv.

Or some press coverage, with seemingly contradictory statements (!):

Month: January 2017

Our universe out of a hologram: Big Bang without a story

Can you hear the echoes from the abyss? If not, come to my talk!