# A direct probe of the evolutionary history of the primordial universe

@article{Chen2016ADP, title={A direct probe of the evolutionary history of the primordial universe}, author={Xingang Chen and Mohammad Hossein Namjoo and Yi Wang}, journal={Science China Physics, Mechanics \& Astronomy}, year={2016}, volume={59}, pages={1-4} }

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…

## 23 Citations

### Unique Fingerprints of Alternatives to Inflation in the Primordial Power Spectrum.

- PhysicsPhysical review letters
- 2019

This Letter introduces a new mechanism through which quantum fluctuations of massive fields function as standard clocks, and the clock signals appear as scale-dependent oscillatory signals in the power spectrum of alternative scenarios to inflation.

### Gravitational production of superheavy dark matter and associated cosmological signatures

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- 2022

Cosmic inflation provides a window to the highest energy densities accessible in nature, far beyond those achievable in any realistic terrestrial experiment. Theoretical insights into the…

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### Non-standard primordial clocks from induced mass in alternative to inflation scenarios

- Physics, EconomicsJournal of Cosmology and Astroparticle Physics
- 2020

In the primordial universe, oscillations of heavy fields can be considered as standard clocks to measure the expansion or contraction history of the universe. Those standard clocks provide a…

### Unsuppressed primordial standard clocks in warm quasi-single field inflation

- PhysicsJournal of Cosmology and Astroparticle Physics
- 2018

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### Revealing the Structure of the Inflationary Landscape through Primordial non-Gaussianity

- Physics
- 2019

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### Non-linear effects in early Universe cosmology

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### Neutrino signatures in primordial non-gaussianities

- PhysicsJournal of High Energy Physics
- 2018

A bstractWe study the cosmological collider phenomenology of neutrinos in an effective field theory. The mass spectrum of neutrinos and their characteristic oscillatory signatures in the squeezed…

### Quantum standard clocks in the primordial trispectrum

- Physics
- 2018

We calculate the primordial trispectrum of curvature perturbation in quasi-single field inflation, with general sound speeds for both the inflaton and the massive scalar. Special attention is paid to…

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