Alan H. Guth

Massachusetts Institute of Technology

Research field

Theoretical cosmology, inflation

Alan Guth proposed in 1981 that the hot Big Bang was preceded by a brief phase of accelerated expansion, which he named inflation. The idea explains why space is flat and why regions of the sky that could never have exchanged a signal have the same temperature. The unit presents the two puzzles, his solution and the predictions that follow from it. The featured article, written after the first Planck results, compares those predictions with the data.

In the masterclass

Section 6 introduces the horizon and flatness problems and inflation as their solution; the spotlight follows the explanation of the exponential expansion.

The research is presented in Unit 14: The Hot Big Bang and the Cosmic Microwave Background, in a research spotlight box that explains the result at the level of the unit and links it to the physics you have just learned.

The paper

Inflationary paradigm after Planck 2013