Shaun Hotchkiss
@justshaun.bsky.social
Cosmology, large scale structure, the early universe.
How researchers communicate, to each other and to the world.
http://youtube.com/CosmologyTalks
https://sharingresearch.com/
How researchers communicate, to each other and to the world.
http://youtube.com/CosmologyTalks
https://sharingresearch.com/
Want to know how to get at the non-linear cosmological scales to test modified gravity, using future large scale structure observations?
Cosmology Talks has your back: youtu.be/nIdCpcObSVU
Cosmology Talks has your back: youtu.be/nIdCpcObSVU
Cosmological Gravity on All Scales | Sankarshana Srinivasan
YouTube video by Cosmology Talks
youtu.be
November 11, 2025 at 4:26 AM
Want to know how to get at the non-linear cosmological scales to test modified gravity, using future large scale structure observations?
Cosmology Talks has your back: youtu.be/nIdCpcObSVU
Cosmology Talks has your back: youtu.be/nIdCpcObSVU
Reposted by Shaun Hotchkiss
Fantastic time discussing whether the latest blockbuster cosmology results really do show that Dark Energy is evolving!
Brilliant explanations from @clairelamman.bsky.social
, @tamarastro.bsky.social and @justshaun.bsky.social
Check it out!
Full talk: youtu.be/reNicLW2vpY?...
🧪⚛️
Brilliant explanations from @clairelamman.bsky.social
, @tamarastro.bsky.social and @justshaun.bsky.social
Check it out!
Full talk: youtu.be/reNicLW2vpY?...
🧪⚛️
Is Dark Matter Evolving? Cosmologists Explain
YouTube video by Bad Boy of Science
youtu.be
April 5, 2025 at 5:16 PM
Fantastic time discussing whether the latest blockbuster cosmology results really do show that Dark Energy is evolving!
Brilliant explanations from @clairelamman.bsky.social
, @tamarastro.bsky.social and @justshaun.bsky.social
Check it out!
Full talk: youtu.be/reNicLW2vpY?...
🧪⚛️
Brilliant explanations from @clairelamman.bsky.social
, @tamarastro.bsky.social and @justshaun.bsky.social
Check it out!
Full talk: youtu.be/reNicLW2vpY?...
🧪⚛️
Reposted by Shaun Hotchkiss
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
Reposted by Shaun Hotchkiss
🥳 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
KiDS Legacy - The Final Cosmology Results
YouTube video by Cosmology Talks
youtu.be
March 26, 2025 at 11:30 AM
Rather appropriately, given this proliferation of "from Home" events, the next one to announce is:
Multiverse from Home!
I suspect discussion won't be hard to come by in this one 😅.
multiverse.cosmodiscussion.com
Multiverse from Home!
I suspect discussion won't be hard to come by in this one 😅.
multiverse.cosmodiscussion.com
Multiverse from Home
multiverse.cosmodiscussion.com
March 25, 2025 at 10:35 AM
Rather appropriately, given this proliferation of "from Home" events, the next one to announce is:
Multiverse from Home!
I suspect discussion won't be hard to come by in this one 😅.
multiverse.cosmodiscussion.com
Multiverse from Home!
I suspect discussion won't be hard to come by in this one 😅.
multiverse.cosmodiscussion.com
Another "from Home" conference has launched (complete with the *perfect* banner image)...
*Tabletop Scale Cosmology*
Register now to discuss, and hear about, how you don't need giant telescopes and colliders to learn about the cosmos!
tabletop.cosmodiscussion.com
*Tabletop Scale Cosmology*
Register now to discuss, and hear about, how you don't need giant telescopes and colliders to learn about the cosmos!
tabletop.cosmodiscussion.com
Tabletop Scale Cosmology
tabletop.cosmodiscussion.com
March 25, 2025 at 12:59 AM
Another "from Home" conference has launched (complete with the *perfect* banner image)...
*Tabletop Scale Cosmology*
Register now to discuss, and hear about, how you don't need giant telescopes and colliders to learn about the cosmos!
tabletop.cosmodiscussion.com
*Tabletop Scale Cosmology*
Register now to discuss, and hear about, how you don't need giant telescopes and colliders to learn about the cosmos!
tabletop.cosmodiscussion.com
Reposted by Shaun Hotchkiss
A nice blog post by Gillian Beltz-Mohrmann about the DESI "unblinding" event last year, the excitement and the reactions:
www.desi.lbl.gov/2025/03/19/a...
www.desi.lbl.gov/2025/03/19/a...
At the Big Reveal: DESI’s December 2024 Unblinding Results
www.desi.lbl.gov
March 20, 2025 at 6:19 PM
A nice blog post by Gillian Beltz-Mohrmann about the DESI "unblinding" event last year, the excitement and the reactions:
www.desi.lbl.gov/2025/03/19/a...
www.desi.lbl.gov/2025/03/19/a...
Reposted by Shaun Hotchkiss
March 20, 2025 at 1:06 AM
Reposted by Shaun Hotchkiss
🔊 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.
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.
No more new Cosmology Talks *today*, I promise!
March 19, 2025 at 10:16 PM
No more new Cosmology Talks *today*, I promise!
Reposted by Shaun Hotchkiss
JUST RELEASED: DESI DR1 & BAO RESULTS FROM DR2🌌
March 19, 2025 at 10:03 PM
JUST RELEASED: DESI DR1 & BAO RESULTS FROM DR2🌌
This is starting to look believable (to me at least 😅)
*Something* is certainly going on...
Great work @desisurvey.bsky.social!
youtu.be/YiRaDtslycE
*Something* is certainly going on...
Great work @desisurvey.bsky.social!
youtu.be/YiRaDtslycE
DESI 2025 - Cosmology Results from DR2 BAO (Garcia-Quintero & Martini)
YouTube video by Cosmology Talks
youtu.be
March 19, 2025 at 10:06 PM
This is starting to look believable (to me at least 😅)
*Something* is certainly going on...
Great work @desisurvey.bsky.social!
youtu.be/YiRaDtslycE
*Something* is certainly going on...
Great work @desisurvey.bsky.social!
youtu.be/YiRaDtslycE
Can't get enough of @ec-euclid.bsky.social?
Here are three "key science areas" the consortium identified from the results today and wanted to talk more about:
- Active Galactic Nuclei
- Galaxy Morphology
- Strong Lensing
youtu.be/YGqaxDH00Yw
Here are three "key science areas" the consortium identified from the results today and wanted to talk more about:
- Active Galactic Nuclei
- Galaxy Morphology
- Strong Lensing
youtu.be/YGqaxDH00Yw
Euclid 2025: AGN, Galaxy Morphology & Strong Lensing (Matamoro, Walmsley & Holloway)
YouTube video by Cosmology Talks
youtu.be
March 19, 2025 at 3:32 PM
Can't get enough of @ec-euclid.bsky.social?
Here are three "key science areas" the consortium identified from the results today and wanted to talk more about:
- Active Galactic Nuclei
- Galaxy Morphology
- Strong Lensing
youtu.be/YGqaxDH00Yw
Here are three "key science areas" the consortium identified from the results today and wanted to talk more about:
- Active Galactic Nuclei
- Galaxy Morphology
- Strong Lensing
youtu.be/YGqaxDH00Yw
Reposted by Shaun Hotchkiss
For an explainer on #Euclid's background and what's in the Q1 data release, here's a conversation between Shaun Hotchkiss (@justshaun.bsky.social), Guada Canas-Herrera (gcanasherrera.com) from @esa.int, and our Herve Aussel (@herveaussel.bsky.social).
www.youtube.com/watch?v=DVlK...
#space 🔭
www.youtube.com/watch?v=DVlK...
#space 🔭
Euclid 2025: Science Goals and Q1 Data Summary (Cañas-Herrera & Aussel)
YouTube video by Cosmology Talks
www.youtube.com
March 19, 2025 at 12:26 PM
For an explainer on #Euclid's background and what's in the Q1 data release, here's a conversation between Shaun Hotchkiss (@justshaun.bsky.social), Guada Canas-Herrera (gcanasherrera.com) from @esa.int, and our Herve Aussel (@herveaussel.bsky.social).
www.youtube.com/watch?v=DVlK...
#space 🔭
www.youtube.com/watch?v=DVlK...
#space 🔭
Reposted by Shaun Hotchkiss
With today’s #Q1Release, we get a preview of #ESAEuclid’s three Deep Fields: North, South and Fornax. 🤩
The location of the Deep Fields can be seen as the yellow patches on this all-sky view of ESA Gaia’s star map from its second data release in 2018, and ESA Planck’s dust map from 2014. (1/3)
The location of the Deep Fields can be seen as the yellow patches on this all-sky view of ESA Gaia’s star map from its second data release in 2018, and ESA Planck’s dust map from 2014. (1/3)
March 19, 2025 at 11:00 AM
With today’s #Q1Release, we get a preview of #ESAEuclid’s three Deep Fields: North, South and Fornax. 🤩
The location of the Deep Fields can be seen as the yellow patches on this all-sky view of ESA Gaia’s star map from its second data release in 2018, and ESA Planck’s dust map from 2014. (1/3)
The location of the Deep Fields can be seen as the yellow patches on this all-sky view of ESA Gaia’s star map from its second data release in 2018, and ESA Planck’s dust map from 2014. (1/3)
27 @eucliduk.bsky.social papers too many to digest?
Cosmology Talks has your back... (more to come later today too!)
youtu.be/DVlKqFrvhRY
Cosmology Talks has your back... (more to come later today too!)
youtu.be/DVlKqFrvhRY
Euclid 2025: Science Goals and Q1 Data Summary (Cañas-Herrera & Aussel)
YouTube video by Cosmology Talks
youtu.be
March 19, 2025 at 11:04 AM
27 @eucliduk.bsky.social papers too many to digest?
Cosmology Talks has your back... (more to come later today too!)
youtu.be/DVlKqFrvhRY
Cosmology Talks has your back... (more to come later today too!)
youtu.be/DVlKqFrvhRY
Reposted by Shaun Hotchkiss
🚨 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 Shaun Hotchkiss
Some further context: cosmologists were anxiously awaiting updates on the Hubble tension. These results mostly close the window for something unexpected to have happened at early times that affects our estimates of the expansion rate of the Universe. 🧪
Latest results from the Atacama Cosmology Telescope: no evidence for any deviations from the standard cosmological model. #cosmology 🧪
Atacama Cosmology Telescope
act.princeton.edu
March 18, 2025 at 5:58 PM
Some further context: cosmologists were anxiously awaiting updates on the Hubble tension. These results mostly close the window for something unexpected to have happened at early times that affects our estimates of the expansion rate of the Universe. 🧪
Reposted by Shaun Hotchkiss
Although #ACT DR6s headline is that LCDM is still king, they do find a 2.5 sigma of an unexplained polarization angle (aka cosmic birefringence)! I am amazed that people are not more excited by this! Their beta = 0.20 \pm 0.08 is very consistent with our Planck+WMAP results! arxiv.org/abs/2205.13962
March 18, 2025 at 7:09 PM
Although #ACT DR6s headline is that LCDM is still king, they do find a 2.5 sigma of an unexplained polarization angle (aka cosmic birefringence)! I am amazed that people are not more excited by this! Their beta = 0.20 \pm 0.08 is very consistent with our Planck+WMAP results! arxiv.org/abs/2205.13962
"DESI's latest results, which will be revealed on March 19"
😲
😲
In its quest to make precision cosmological measurements, DESI uses a process called “blinding” in its analysis methodology in order to avoid the inaccuracies that can arise from confirmation bias. This process was especially important for DESI’s latest results, which will be revealed on March 19🚀
March 12, 2025 at 6:55 PM
"DESI's latest results, which will be revealed on March 19"
😲
😲
Exciting times in cosmology... it's certainly curious that any combination of two probes from CMB, BAO and Supernovae, seems to favour evolving dark energy. With all three combined it's very strong, but it's still there with any two
And now, with these DES results, one doesn't even need DESI's BAO.
And now, with these DES results, one doesn't even need DESI's BAO.
Dark Energy Survey: implications for cosmological expansion models from the final DES Baryon Acoustic Oscillation and Supernova data
The Dark Energy Survey (DES) recently released the final results of its two principal probes of the expansion history: Type Ia Supernovae (SNe) and Baryonic Acoustic Oscillations (BAO). In this paper,...
arxiv.org
March 12, 2025 at 10:24 AM
Exciting times in cosmology... it's certainly curious that any combination of two probes from CMB, BAO and Supernovae, seems to favour evolving dark energy. With all three combined it's very strong, but it's still there with any two
And now, with these DES results, one doesn't even need DESI's BAO.
And now, with these DES results, one doesn't even need DESI's BAO.
(This is not a formal announcement but...)
Registration for @cosmofromhome this year is technically open (cosmologyfromhome.com/registration/)
Bonus! If you register now you get to suggest plenary speakers/topics for us to invite😃.
Formal announcements will come soon-ish O(weeks)...
Registration for @cosmofromhome this year is technically open (cosmologyfromhome.com/registration/)
Bonus! If you register now you get to suggest plenary speakers/topics for us to invite😃.
Formal announcements will come soon-ish O(weeks)...
Registration – Cosmology from Home
cosmologyfromhome.com
March 10, 2025 at 3:31 AM
(This is not a formal announcement but...)
Registration for @cosmofromhome this year is technically open (cosmologyfromhome.com/registration/)
Bonus! If you register now you get to suggest plenary speakers/topics for us to invite😃.
Formal announcements will come soon-ish O(weeks)...
Registration for @cosmofromhome this year is technically open (cosmologyfromhome.com/registration/)
Bonus! If you register now you get to suggest plenary speakers/topics for us to invite😃.
Formal announcements will come soon-ish O(weeks)...
The publicly available talks from Early Universe from Home are all now available here: www.youtube.com/watch?v=K2Cr...
Niki Suckau - Scalarverse: A Unified Framework for Nonlinear Post-Inflationary Dynamics
YouTube video by from Home Conferences
www.youtube.com
March 7, 2025 at 1:54 PM
The publicly available talks from Early Universe from Home are all now available here: www.youtube.com/watch?v=K2Cr...