A Direct Probe of the Evolutionary History of the Primordial Universe

TL;DR

This paper proposes using massive fields as standard clocks to directly measure the universe's evolution during the primordial era, offering new evidence for the Big Bang scenario.

Contribution

It introduces the concept of primordial standard clocks using massive fields, extending direct measurement techniques to the early universe.

Findings

Theoretical framework for primordial standard clocks

Potential to provide direct evidence for Big Bang models

Extension of cosmological measurement methods

Abstract

Since Hubble and Lamaitre's discovery of the expanding universe using galaxies till the recent discovery of the accelerating universe using standard candles, direct measurements of the evolution of the scale factor of the universe a(t) have played central roles in establishing the standard model of cosmology. In this letter, we show that such a measurement may be extended to the primordial universe using massive fields as standard clocks, providing a direct evidence for the scenario responsible for the Big Bang. This is a short and non-technical introduction to the idea of classical and quantum primordial standard clocks.