Thomas Colas

📢Registration open for Contours 2026 — EFTs Meet the Schwinger–Keldysh Formalism! 📅 29 June – 3 July 2026 📍 DAMTP, University of Cambridge Join us for a conference on non-equilibrium EFTs across #hydrodynamics, #blackholes, #holography & #cosmology indico.global/event/16432/ov…

Partie 2/2 : youtube.com/watch?v=48MR7B…

[FR] Voici un petit cours introductif au formalisme de Schwinger-Keldysh pour les systèmes ouverts et hors-équilibres en cosmologie 🧑‍🏫 🌌 Merci au @CEAstrophysique pour l'accueil et les échanges ! Partie 1/2: youtube.com/watch?v=fgLAh5…

Quel bruit fait l'Univers ? Un chercheur de l'Université de John Hopkins a tenté de répondre à cette question ! On estime que toutes les minutes, quelque part dans l'Univers observable, deux trous noirs entrent en collision et émettent alors un puissant signal d'ondes ...

Here is our poster 😁

📢Registration open for Contours 2026 — EFTs Meet the Schwinger–Keldysh Formalism! 📅 29 June – 3 July 2026 📍 DAMTP, University of Cambridge Join us for a conference on non-equilibrium EFTs across #hydrodynamics, #blackholes, #holography & #cosmology indico.global/event/16432/ov…

Cosmological Correlators: Theory and Phenomenology Guilherme Pimentel Website: courses.ipht.fr/?q=en%2Fnode%2…

@LucienHeurtier Thanks a lot @LucienHeurtier 🙏 It has been an exciting week for PNG and CMB bispectrum on the @arxiv so far📡🛰️

One of two extremely interesting papers from @CosmoColas and collaborators on the open EFT of inflation and how it can be proved with cosmological data. Worth having a look!

Arxiv link: arxiv.org/abs/2603.13473

This opens a model-independent observational window onto primordial dissipation and noise, providing a new avenue to discriminate between early-Universe scenarios using CMB non-Gaussianity. Excited to see how future data, in particular LSS, will sharpen these constraints! ☄️

🛰️New paper out on arXiv! We explore how dissipation and noise during inflation leave observable imprints in the CMB, using the Open EFT of Inflation (Open EFToI) 🧵👇 #cosmology #physics @Cambridge_Uni arxiv.org/pdf/2603.13473

@bhavaytyagi Thanks! The metric is the system, the dark sector is the environment. As in a medium where EM waves mix with collective excitations (e.g. plasmons), the coupling gives rise to an emergent scalar dof associated with the medium’s dynamics. That’s what we call the open dark fluid

@CosmoColas This is really cool. Im curious, What’s the environment here? What makes the gravitational system open?

Phenomenology of an Open EFT of Dark Energy 🌌 📄arxiv.org/abs/2603.12321 All current evidence for dark matter and dark energy is purely gravitational. Hence, we treat the dark sector as the medium through which the spacetime metric propagates #cosmology #darkenergy Thread 👇

@CburgesCliff Thanks @CburgesCliff I would be curious to know whether your axio-dilaton model can be matched to this EFT (or an extension of it) in some regime. I let you know if I take a step in that direction 😄

@CosmoColas Congratulations Thomas!

Open gravitational dynamics offers an alternative perspective on the dark sector. This model fits current data and predicts correlated signatures in GW, galaxy clustering and weak lensing, offering multiple observational tests in upcoming surveys. Exciting prospects ahead!🌜

The model predicts enhanced structures at low z compared to Lambda-CDM. This enhancement places this minimal scenario outside the observationally allowed range, though precise bounds would require scanning over cosmological parameters and a precise inclusion of baryons