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/
In ΛCDM there seems to be a genuine "Omega_m" tension between probes... in wo,wa it goes away...
(see DES Y5 vs DESI DR2 BAO)
(see DES Y5 vs DESI DR2 BAO)
March 19, 2025 at 10:26 PM
In ΛCDM there seems to be a genuine "Omega_m" tension between probes... in wo,wa it goes away...
(see DES Y5 vs DESI DR2 BAO)
(see DES Y5 vs DESI DR2 BAO)
Not to mention that neutrinos masses in ΛCDM with neutrinos masses looks very suspicious, because it is starting to rule out the lower bound from particles physics...
But in wo,wa it goes back to being all fine...
But in wo,wa it goes back to being all fine...
March 19, 2025 at 10:26 PM
Not to mention that neutrinos masses in ΛCDM with neutrinos masses looks very suspicious, because it is starting to rule out the lower bound from particles physics...
But in wo,wa it goes back to being all fine...
But in wo,wa it goes back to being all fine...
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.
Is parity violated on cosmological scales in the universe?
I don't know, but I do know where to go to find the latest expert opinions on the topic!
Parity Violation from Home: parity.cosmodiscussion.com
(The talk submission deadline is *technically* this Friday!!!)
I don't know, but I do know where to go to find the latest expert opinions on the topic!
Parity Violation from Home: parity.cosmodiscussion.com
(The talk submission deadline is *technically* this Friday!!!)
October 23, 2024 at 7:39 AM
Is parity violated on cosmological scales in the universe?
I don't know, but I do know where to go to find the latest expert opinions on the topic!
Parity Violation from Home: parity.cosmodiscussion.com
(The talk submission deadline is *technically* this Friday!!!)
I don't know, but I do know where to go to find the latest expert opinions on the topic!
Parity Violation from Home: parity.cosmodiscussion.com
(The talk submission deadline is *technically* this Friday!!!)
Want to come to an innovative and *good* online conference about Neutrinos at the interface of cosmology and particle physics?
Neutrinos from Home is what you're looking for!
Registration open... (tell your friends!)
neutrinos.cosmodiscussion.com
Neutrinos from Home is what you're looking for!
Registration open... (tell your friends!)
neutrinos.cosmodiscussion.com
February 28, 2024 at 4:19 AM
Want to come to an innovative and *good* online conference about Neutrinos at the interface of cosmology and particle physics?
Neutrinos from Home is what you're looking for!
Registration open... (tell your friends!)
neutrinos.cosmodiscussion.com
Neutrinos from Home is what you're looking for!
Registration open... (tell your friends!)
neutrinos.cosmodiscussion.com
The tension is essentially in the spectral index of the matter power spectrum.
The Lyman Alpha data really wants the slope of the spectrum to be much steeper on the smaller scales it measures, than CMB wants it to be on CMB scales.
The Lyman Alpha data really wants the slope of the spectrum to be much steeper on the smaller scales it measures, than CMB wants it to be on CMB scales.
January 12, 2024 at 9:29 AM
The tension is essentially in the spectral index of the matter power spectrum.
The Lyman Alpha data really wants the slope of the spectrum to be much steeper on the smaller scales it measures, than CMB wants it to be on CMB scales.
The Lyman Alpha data really wants the slope of the spectrum to be much steeper on the smaller scales it measures, than CMB wants it to be on CMB scales.
The tension can be resolved by 3 different models (not neutrino masses though).
1) A running of the spectral index (with an amplitude fully allowed by Planck data)
2) A sub-component of about 5% of warm dark matter
3) A sub-component of about 5% of ulralight axion dark matter
1) A running of the spectral index (with an amplitude fully allowed by Planck data)
2) A sub-component of about 5% of warm dark matter
3) A sub-component of about 5% of ulralight axion dark matter
January 12, 2024 at 9:28 AM
The tension can be resolved by 3 different models (not neutrino masses though).
1) A running of the spectral index (with an amplitude fully allowed by Planck data)
2) A sub-component of about 5% of warm dark matter
3) A sub-component of about 5% of ulralight axion dark matter
1) A running of the spectral index (with an amplitude fully allowed by Planck data)
2) A sub-component of about 5% of warm dark matter
3) A sub-component of about 5% of ulralight axion dark matter
It seems like the whole Alens thing has also evaporated in the latest Planck release (PR4).
What are the physical changes to their likelihood that caused this shift? (i.e. what is different in Camspec/Hillipop vs Plik?)
What are the physical changes to their likelihood that caused this shift? (i.e. what is different in Camspec/Hillipop vs Plik?)
September 26, 2023 at 11:15 PM
It seems like the whole Alens thing has also evaporated in the latest Planck release (PR4).
What are the physical changes to their likelihood that caused this shift? (i.e. what is different in Camspec/Hillipop vs Plik?)
What are the physical changes to their likelihood that caused this shift? (i.e. what is different in Camspec/Hillipop vs Plik?)
With Planck shifting S8 down 1σ in their recent release, and re-analyses of cosmic shear shifting it up, is the S8 "tension" resolved?
Both claim ~1.5σ difference, but compare to older versions of each other's analyses, so it must be even less?
arxiv.org/abs/2309.10034
arxiv.org/abs/2305.17173
Both claim ~1.5σ difference, but compare to older versions of each other's analyses, so it must be even less?
arxiv.org/abs/2309.10034
arxiv.org/abs/2305.17173
September 26, 2023 at 11:12 PM
With Planck shifting S8 down 1σ in their recent release, and re-analyses of cosmic shear shifting it up, is the S8 "tension" resolved?
Both claim ~1.5σ difference, but compare to older versions of each other's analyses, so it must be even less?
arxiv.org/abs/2309.10034
arxiv.org/abs/2305.17173
Both claim ~1.5σ difference, but compare to older versions of each other's analyses, so it must be even less?
arxiv.org/abs/2309.10034
arxiv.org/abs/2305.17173
Oddly enough, one of the best ways to learn about dark matter is through its interaction with light.
(Gravitationally!)
You can explore, and learn about, gravitational lensing in The Hunt for Dark Matter web app
gravitational-lensing.explored.info
(Gravitationally!)
You can explore, and learn about, gravitational lensing in The Hunt for Dark Matter web app
gravitational-lensing.explored.info
September 4, 2023 at 9:40 PM
Oddly enough, one of the best ways to learn about dark matter is through its interaction with light.
(Gravitationally!)
You can explore, and learn about, gravitational lensing in The Hunt for Dark Matter web app
gravitational-lensing.explored.info
(Gravitationally!)
You can explore, and learn about, gravitational lensing in The Hunt for Dark Matter web app
gravitational-lensing.explored.info