Thomas Colas
@cosmocolas.bsky.social
Postdoc in #cosmology at DAMTP @Cambridge_Uni | #earlyuniverse and #openEFTs 🌌
Pinned
Thomas Colas
@cosmocolas.bsky.social
· Jul 8
An Open System Approach to Gravity
Several major open problems in cosmology, including the nature of inflation, dark matter, and dark energy, share a common structure: they involve spacetime-filling media with unknown microphysics, and...
arxiv.org
What if dark matter and dark energy are the medium through which photons and gravitational waves reach us? In our new work, we take a materials-science perspective — and characterize the macroscopic properties of these mysterious cosmic substances arxiv.org/abs/2507.03103 #physics #quantum [1/25]
Last summer I taught at the Disordered Universe Summer School — an interdisciplinary program on de Sitter physics, cosmology, holography, scattering amplitudes, and open/disordered systems. I prepared lecture notes on Open Effective Field Theories, now on arXiv📜 arxiv.org/abs/2510.00140
Lectures on Open Effective Field Theories
Effective field theories offer a powerful method to unify diverse models under a small set of control parameters, allowing systematic expansions around well-established theories. These techniques, dev...
arxiv.org
October 2, 2025 at 1:29 PM
Last summer I taught at the Disordered Universe Summer School — an interdisciplinary program on de Sitter physics, cosmology, holography, scattering amplitudes, and open/disordered systems. I prepared lecture notes on Open Effective Field Theories, now on arXiv📜 arxiv.org/abs/2510.00140
What’s the best way to extract information about the early universe? In our new paper, we tackle this classic cosmology problem using tools from quantum information theory🧵[1/20] #Physics #Cosmology #Quantum
arxiv.org/abs/2507.12228
arxiv.org/abs/2507.12228
Quantum estimation of cosmological parameters
Understanding how well future cosmological experiments can reconstruct the mechanism that generated primordial inhomogeneities is key to assessing the extent to which cosmology can inform fundamental ...
arxiv.org
July 17, 2025 at 9:02 AM
What’s the best way to extract information about the early universe? In our new paper, we tackle this classic cosmology problem using tools from quantum information theory🧵[1/20] #Physics #Cosmology #Quantum
arxiv.org/abs/2507.12228
arxiv.org/abs/2507.12228
What if dark matter and dark energy are the medium through which photons and gravitational waves reach us? In our new work, we take a materials-science perspective — and characterize the macroscopic properties of these mysterious cosmic substances arxiv.org/abs/2507.03103 #physics #quantum [1/25]
An Open System Approach to Gravity
Several major open problems in cosmology, including the nature of inflation, dark matter, and dark energy, share a common structure: they involve spacetime-filling media with unknown microphysics, and...
arxiv.org
July 8, 2025 at 9:07 AM
What if dark matter and dark energy are the medium through which photons and gravitational waves reach us? In our new work, we take a materials-science perspective — and characterize the macroscopic properties of these mysterious cosmic substances arxiv.org/abs/2507.03103 #physics #quantum [1/25]
Reposted by Thomas Colas
New joint SPT, ACT, & Planck CMB lensing power spectrum & cosmology results! The CMB measurements are consistent, when combined place new leading constraints on cosmic structure, the Hubble constant, and the neutrino mass! @NSF @doescience #southpole arxiv.org/abs/2504.20038
May 5, 2025 at 5:20 PM
New joint SPT, ACT, & Planck CMB lensing power spectrum & cosmology results! The CMB measurements are consistent, when combined place new leading constraints on cosmic structure, the Hubble constant, and the neutrino mass! @NSF @doescience #southpole arxiv.org/abs/2504.20038
Reposted by Thomas Colas
New SPT-3G B-mode spectrum and r-constraint! "demonstrates a white noise level of 9.3 (6.7) µK-arcmin at ℓ∼500 for the 95GHz (150GHz) data, with a 1/ℓ noise knee at ℓ= 128 (182) with a statistical uncertainty on r of σ(r) = 0.067" arxiv.org/abs/2505.02827 @NSF @doescience
May 6, 2025 at 2:43 AM
New SPT-3G B-mode spectrum and r-constraint! "demonstrates a white noise level of 9.3 (6.7) µK-arcmin at ℓ∼500 for the 95GHz (150GHz) data, with a 1/ℓ noise knee at ℓ= 128 (182) with a statistical uncertainty on r of σ(r) = 0.067" arxiv.org/abs/2505.02827 @NSF @doescience
Reposted by Thomas Colas
First aurora of the 2025 winter season! Picture by SPT winterover Sim Bash! @noaa.gov #NSFfunded
April 18, 2025 at 2:29 AM
First aurora of the 2025 winter season! Picture by SPT winterover Sim Bash! @noaa.gov #NSFfunded
Reposted by Thomas Colas
Physicists suspect that spinning neutron stars, known as pulsars, resemble something of a cosmic baked ziti: solid outer crust, with an interior of pressurized neutrons that can bear an uncanny resemblance to gnocchi, spaghetti, and lasagna. www.quantamagazine.org/physicists-s...
April 15, 2025 at 8:06 PM
Physicists suspect that spinning neutron stars, known as pulsars, resemble something of a cosmic baked ziti: solid outer crust, with an interior of pressurized neutrons that can bear an uncanny resemblance to gnocchi, spaghetti, and lasagna. www.quantamagazine.org/physicists-s...
Reposted by Thomas Colas
MIT following Harvard's lead here
April 15, 2025 at 1:07 AM
MIT following Harvard's lead here
Reposted by Thomas Colas
Two-weeks after #Sunset, the sky is getting darker at the #southpole. Pic of SPT winterover Karia Dibert by Sim Bash, outside doing the greasing of the SPT elevation gears of the telescope, that they still need to do every two weeks, even during the depths of winter.
@NSF
@NSF
April 7, 2025 at 4:59 PM
Two-weeks after #Sunset, the sky is getting darker at the #southpole. Pic of SPT winterover Karia Dibert by Sim Bash, outside doing the greasing of the SPT elevation gears of the telescope, that they still need to do every two weeks, even during the depths of winter.
@NSF
@NSF
Reposted by Thomas Colas
Picture of SPT winterover Karia Dibert cleaning the snow off the cabin roof of the telescope, a few days after #equinox #sunset at the South Pole! #Antarctica @NSF
March 31, 2025 at 10:58 PM
Picture of SPT winterover Karia Dibert cleaning the snow off the cabin roof of the telescope, a few days after #equinox #sunset at the South Pole! #Antarctica @NSF
Reposted by Thomas Colas
Unfortunately it was pretty cloud during #Sunset this year at the South Pole, but our winterover Sim managed to catch this picture just before the weather got bad, with the moon over SPT! #southpole #Antarctica
March 30, 2025 at 4:06 PM
Unfortunately it was pretty cloud during #Sunset this year at the South Pole, but our winterover Sim managed to catch this picture just before the weather got bad, with the moon over SPT! #southpole #Antarctica
Very happy to share the announcement for the summer school "The Disordered Universe", from July 21 to August 1 in As Barreiras, Spain: indico.sns.it/event/91/ove...
Program: de Sitter physics, holography, scattering amplitudes, open systems and disordered systems 🌌
Registration open until April 6
Program: de Sitter physics, holography, scattering amplitudes, open systems and disordered systems 🌌
Registration open until April 6
Summer School on The Disordered Universe
The school aims to attract graduate students as well as young postdocs interested in the areas of de Sitter physics, theoretical cosmology, holography, scattering amplitudes, open systems, and disorde...
indico.sns.it
March 28, 2025 at 5:39 PM
Very happy to share the announcement for the summer school "The Disordered Universe", from July 21 to August 1 in As Barreiras, Spain: indico.sns.it/event/91/ove...
Program: de Sitter physics, holography, scattering amplitudes, open systems and disordered systems 🌌
Registration open until April 6
Program: de Sitter physics, holography, scattering amplitudes, open systems and disordered systems 🌌
Registration open until April 6
Reposted by Thomas Colas
Too busy to read the paper? Want the inside scoop? (6-month B-mode saga, surprise at unblinding, quintupling of our spectroscopic calibration sample, methodology updates!) What erased the S8 tension? @justshaun.bsky.social has asked all the questions for you! 🔭
🍿: www.youtube.com/watch?v=PIQK...
🍿: www.youtube.com/watch?v=PIQK...
March 26, 2025 at 12:55 PM
Too busy to read the paper? Want the inside scoop? (6-month B-mode saga, surprise at unblinding, quintupling of our spectroscopic calibration sample, methodology updates!) What erased the S8 tension? @justshaun.bsky.social has asked all the questions for you! 🔭
🍿: www.youtube.com/watch?v=PIQK...
🍿: www.youtube.com/watch?v=PIQK...
Reposted by Thomas Colas
This is slightly ahead of the official announcement, but:
⚡CONFERENCE ALERT⚡
Don't miss out on Cosmology from Home 2025!
The dates have been fixed at 16 June – 27 June. Check out our confirmed plenary speakers (and register!) at cosmologyfromhome.com!
⚡CONFERENCE ALERT⚡
Don't miss out on Cosmology from Home 2025!
The dates have been fixed at 16 June – 27 June. Check out our confirmed plenary speakers (and register!) at cosmologyfromhome.com!
Cosmology from Home
cosmologyfromhome.com
March 26, 2025 at 1:20 PM
This is slightly ahead of the official announcement, but:
⚡CONFERENCE ALERT⚡
Don't miss out on Cosmology from Home 2025!
The dates have been fixed at 16 June – 27 June. Check out our confirmed plenary speakers (and register!) at cosmologyfromhome.com!
⚡CONFERENCE ALERT⚡
Don't miss out on Cosmology from Home 2025!
The dates have been fixed at 16 June – 27 June. Check out our confirmed plenary speakers (and register!) at cosmologyfromhome.com!
Reposted by Thomas Colas
🥳 It's paper day for the completed #ESO Kilo-Degree Survey. We end our journey with a consistent picture of #cosmology 😲
I've been co-leading KiDS for 12yrs & I'm so proud of what the team's achieved. If you're at the #Euclid meet, go to Angus Wright's talk @10am today!🔭
ℹ️: arxiv.org/pdf/2503.19441
I've been co-leading KiDS for 12yrs & I'm so proud of what the team's achieved. If you're at the #Euclid meet, go to Angus Wright's talk @10am today!🔭
ℹ️: arxiv.org/pdf/2503.19441
March 26, 2025 at 8:01 AM
🥳 It's paper day for the completed #ESO Kilo-Degree Survey. We end our journey with a consistent picture of #cosmology 😲
I've been co-leading KiDS for 12yrs & I'm so proud of what the team's achieved. If you're at the #Euclid meet, go to Angus Wright's talk @10am today!🔭
ℹ️: arxiv.org/pdf/2503.19441
I've been co-leading KiDS for 12yrs & I'm so proud of what the team's achieved. If you're at the #Euclid meet, go to Angus Wright's talk @10am today!🔭
ℹ️: arxiv.org/pdf/2503.19441
Reposted by Thomas Colas
New OSIRIS-APEX poster celebrating perihelion passages.
March 26, 2025 at 8:33 PM
New OSIRIS-APEX poster celebrating perihelion passages.
Reposted by Thomas Colas
While the headline takeaway from the ACT results yesterday was "LCDM is fine", the headline from DESI is quite different - evidence for evolving dark energy, at up to 4.2 sigma, and over 3 sigma even without any supernovae, which persists with many different combinations of datasets. 🧪🔭
March 19, 2025 at 10:15 PM
While the headline takeaway from the ACT results yesterday was "LCDM is fine", the headline from DESI is quite different - evidence for evolving dark energy, at up to 4.2 sigma, and over 3 sigma even without any supernovae, which persists with many different combinations of datasets. 🧪🔭
Reposted by Thomas Colas
I find this four parameter binned w(z) plot from DESI tantalising... the preference for w0,wa isn't coming from one isolated redshift.
March 19, 2025 at 10:26 PM
I find this four parameter binned w(z) plot from DESI tantalising... the preference for w0,wa isn't coming from one isolated redshift.
Reposted by Thomas Colas
JUST RELEASED: DESI DR1 & BAO RESULTS FROM DR2🌌
March 19, 2025 at 10:03 PM
JUST RELEASED: DESI DR1 & BAO RESULTS FROM DR2🌌
Reposted by Thomas Colas
🔊 New BAO analysis from the 3-year observations (DR2). Long story short, as follows.
1. DESI alone is consistent with LCDM. 👉 Boring
2. DESI and Planck have a 2.3 discrepancy in Ωm-H0rd plane. 👉Interesting.
1. DESI alone is consistent with LCDM. 👉 Boring
2. DESI and Planck have a 2.3 discrepancy in Ωm-H0rd plane. 👉Interesting.
March 20, 2025 at 1:12 AM
🔊 New BAO analysis from the 3-year observations (DR2). Long story short, as follows.
1. DESI alone is consistent with LCDM. 👉 Boring
2. DESI and Planck have a 2.3 discrepancy in Ωm-H0rd plane. 👉Interesting.
1. DESI alone is consistent with LCDM. 👉 Boring
2. DESI and Planck have a 2.3 discrepancy in Ωm-H0rd plane. 👉Interesting.
Reposted by Thomas Colas
If the mounting evidence of weakening dark energy holds up, it would upend cosmologists’ understanding of our ultimate destiny. @walkingthedot.bsky.social reports:
March 19, 2025 at 10:00 PM
If the mounting evidence of weakening dark energy holds up, it would upend cosmologists’ understanding of our ultimate destiny. @walkingthedot.bsky.social reports:
Reposted by Thomas Colas
Reposted by Thomas Colas
ACT (Atacama Cosmology Telescope) comes out strongly in favor of the Maximally Boring Universe: "no statistically significant preference for a departure from the
baseline ΛCDM model."
act.princeton.edu/sites/g/file...
baseline ΛCDM model."
act.princeton.edu/sites/g/file...
March 18, 2025 at 6:04 PM
ACT (Atacama Cosmology Telescope) comes out strongly in favor of the Maximally Boring Universe: "no statistically significant preference for a departure from the
baseline ΛCDM model."
act.princeton.edu/sites/g/file...
baseline ΛCDM model."
act.princeton.edu/sites/g/file...
Reposted by Thomas Colas
🚨 BIG NEWS ALERT! 🚨
We’re just 24 HOURS AWAY from a MAJOR DESI release! 🌉🔭
Tomorrow at 3 PM PT, DESI is unveiling DR1, our first official Data Release—the largest dataset of its kind, packed with information on 18.7 million galaxies, quasars, and stars! But that’s not all…
We’re just 24 HOURS AWAY from a MAJOR DESI release! 🌉🔭
Tomorrow at 3 PM PT, DESI is unveiling DR1, our first official Data Release—the largest dataset of its kind, packed with information on 18.7 million galaxies, quasars, and stars! But that’s not all…
March 18, 2025 at 10:11 PM
🚨 BIG NEWS ALERT! 🚨
We’re just 24 HOURS AWAY from a MAJOR DESI release! 🌉🔭
Tomorrow at 3 PM PT, DESI is unveiling DR1, our first official Data Release—the largest dataset of its kind, packed with information on 18.7 million galaxies, quasars, and stars! But that’s not all…
We’re just 24 HOURS AWAY from a MAJOR DESI release! 🌉🔭
Tomorrow at 3 PM PT, DESI is unveiling DR1, our first official Data Release—the largest dataset of its kind, packed with information on 18.7 million galaxies, quasars, and stars! But that’s not all…
Reposted by Thomas Colas
Kinematic flow and the emergence of time
Guilherme Pimentel
(March 4th, 2025)
Abstract: bhaumik-institute.physics.ucla.edu/sites/defaul...
youtu.be/WjiyFUv7LtQ?...
Guilherme Pimentel
(March 4th, 2025)
Abstract: bhaumik-institute.physics.ucla.edu/sites/defaul...
youtu.be/WjiyFUv7LtQ?...
Guilherme Leite Pimentel (SNS Pisa), "Kinematic flow and the emergence of time"
YouTube video by Bhaumik Institute
youtu.be
March 7, 2025 at 3:17 AM
Kinematic flow and the emergence of time
Guilherme Pimentel
(March 4th, 2025)
Abstract: bhaumik-institute.physics.ucla.edu/sites/defaul...
youtu.be/WjiyFUv7LtQ?...
Guilherme Pimentel
(March 4th, 2025)
Abstract: bhaumik-institute.physics.ucla.edu/sites/defaul...
youtu.be/WjiyFUv7LtQ?...