Thomas Colas

Postdoc in #cosmology at DAMTP @Cambridge_Uni | #earlyuniverse and #openEFTs 🌌

Bluesky: @cosmocolas.bsky.social 🦋

[Thomas Colas @CosmoColas]

A huge thank you to everyone who joined the Contours 2026 conference and made it such a lively event! I'm very grateful to all the participants, speakers, and admin teams who helped make it happen. It has been a fantastic week of discussions 🌌🕳️🌊🪞
https://t.co/V2ONOikyW4

[Lucien Heurtier @LucienHeurtier]

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If you didn't, PM me. We need as many ECRs to fill it asap, and you could help spread it.

If you were, spread it!🧪

[Thomas Colas @CosmoColas]

@WilmsRolf Absolutely, I completely agree. I also find it truly fascinating how much we can infer about such inaccessible physics from the primordial perturbations, despite knowing so little about the microscopic origin of inflation itself. Thanks a lot for the comment!

[Thomas Colas @CosmoColas]

8/ On CMB scales Δθₖ* ~ e⁻¹¹⁷.
This gives a new inflationary consistency relation: the primordial power spectrum fixes the phase uncertainty🧭
A measurable loss of coherence would point to new primordial physics: non-adiabaticity or decoherence.

[Thomas Colas @CosmoColas]

1/ 📄 New paper’s out: we study phase coherence in primordial #cosmology.
The sharp acoustic peaks of the CMB and their late-time imprint in BAO require primordial perturbations to oscillate with extremely coherent phases.
What fixes this coherence? 🧵
https://t.co/fEbeMnbLyT

[Thomas Colas @CosmoColas]

7/ In fact, the result is insensitive to essentially any intermediate expansion history: prolonged reheating/preheating, early matter or PBH domination, kination, early dark energy, or a time-dependent equation of state.
None changes the final coherence if ζ is conserved.

[Thomas Colas @CosmoColas]

Many thanks to everyone who discussed stochastic inflation, Schwinger–Keldysh EFTs and RG ideas with us over the past months. Discussions and feedback were extremely valuable throughout this project 🙏

[Thomas Colas @CosmoColas]

📄 New paper with Sebastián Céspedes🌌🌊
We revisit stochastic inflation from the viewpoint of Schwinger–Keldysh EFTs and Wilsonian RG.
Main message: stochastic inflation emerges as the IR limit of a real-time Wilsonian RG flow
https://t.co/YAugjvdfx3
#cosmology #qft #physics🧵

[Thomas Colas @CosmoColas]

This perspective opens many directions for stochastic inflation:
🔄 non-equilibrium RG flows
📉 infrared fixed points
⚛️ power counting and operator hierarchies
🌊 non-equilibrium steady states
and more generally a Wilsonian understanding of real-time cosmological evolution.