Lucien Heurtier
@lucienheurtier.bsky.social
Theoretical Physicist at King's Coll. London @KCL_Physics #cosmology, #particles, #Universe, #darkmatter, #blackholes. Write fast, the Universe expands...
https://lheurtier.github.io/index.html
https://lheurtier.github.io/index.html
Pinned
I'm new to this, but I just created a list dedicated to Primordial Black Hole physics!
bsky.app/profile/did:...
bsky.app/profile/did:...
I am extremely pleased to share this paper I wrote with Jean Alexandre and Silvia Pla. In a few words: The dynamics of any reasonable cosmic inflation model need to account for the RG evolution of the inflation potential! A thread below 🧵👇
arxiv.org/abs/2511.05296
arxiv.org/abs/2511.05296
Exact Renormalisation Group Evolution of the Inflation Dynamics: Reconciling $α$-Attractors with ACT
We present a non-perturbative framework for the dynamics of slow-roll inflation that consistently incorporates quantum corrections, based on an alternative functional renormalisation group (RG) approa...
arxiv.org
November 10, 2025 at 12:31 PM
I am extremely pleased to share this paper I wrote with Jean Alexandre and Silvia Pla. In a few words: The dynamics of any reasonable cosmic inflation model need to account for the RG evolution of the inflation potential! A thread below 🧵👇
arxiv.org/abs/2511.05296
arxiv.org/abs/2511.05296
Today, I published this paper on recent CMB observations vs Lyman-alpha constraints on the primordial power spectrum, and how it favours inflation potential with localised features. A thread!🧵👇
November 4, 2025 at 9:36 AM
Today, I published this paper on recent CMB observations vs Lyman-alpha constraints on the primordial power spectrum, and how it favours inflation potential with localised features. A thread!🧵👇
That's the terror of knowing what this world is about
Watchin' some good friends screamin', "Let me out"
Pray tomorrow gets me higher
Pressure on people, people on streets!
#nokings
Watchin' some good friends screamin', "Let me out"
Pray tomorrow gets me higher
Pressure on people, people on streets!
#nokings
October 19, 2025 at 9:46 AM
That's the terror of knowing what this world is about
Watchin' some good friends screamin', "Let me out"
Pray tomorrow gets me higher
Pressure on people, people on streets!
#nokings
Watchin' some good friends screamin', "Let me out"
Pray tomorrow gets me higher
Pressure on people, people on streets!
#nokings
First time I had to review an AI-generated article.
This is going to get harder and harder.
This is going to get harder and harder.
August 21, 2025 at 9:10 AM
First time I had to review an AI-generated article.
This is going to get harder and harder.
This is going to get harder and harder.
Unconverged MCMC corner plots are psychedelic. I think I will eventually open an art gallery. #cosmology #art #science
July 10, 2025 at 11:09 AM
Unconverged MCMC corner plots are psychedelic. I think I will eventually open an art gallery. #cosmology #art #science
After an intense week of organising two different conferences, now flying to Munich to relax and chat physics... and opening a little gem on the way!! Very comprehensive textbook! Strongly recommend it!
June 9, 2025 at 7:18 AM
After an intense week of organising two different conferences, now flying to Munich to relax and chat physics... and opening a little gem on the way!! Very comprehensive textbook! Strongly recommend it!
Yesterday, we hosted @kingsnmes.bsky.social King's College London the first edition of the UK-APP conference series, a new platform for discussion in astroparticle physics phenomenology funded by the IoP.
The winter edition of the conference will be hosted by Manchester University, stay tuned!
The winter edition of the conference will be hosted by Manchester University, stay tuned!
June 3, 2025 at 9:44 AM
Yesterday, we hosted @kingsnmes.bsky.social King's College London the first edition of the UK-APP conference series, a new platform for discussion in astroparticle physics phenomenology funded by the IoP.
The winter edition of the conference will be hosted by Manchester University, stay tuned!
The winter edition of the conference will be hosted by Manchester University, stay tuned!
After a few weeks off social media I open Bluesky hoping to read lots of new exciting research initiatives, but the most I read about is how visa fees in the UK and the Trump admin in the US are endangering past initiatives. Truly depressing.
April 23, 2025 at 7:41 AM
After a few weeks off social media I open Bluesky hoping to read lots of new exciting research initiatives, but the most I read about is how visa fees in the UK and the Trump admin in the US are endangering past initiatives. Truly depressing.
This plane company deeply cares about what their customers read.
No crappy magazines allowed 😄
No crappy magazines allowed 😄
April 1, 2025 at 2:57 PM
This plane company deeply cares about what their customers read.
No crappy magazines allowed 😄
No crappy magazines allowed 😄
Can somebody explain to me what the heck is the usefulness of referencing a "private communication" in a paper?
Really sounds to me like "I used some secret scientific fact that some famous person told me about, so you've got to believe it, and sorry but you can't check it, it's private" 😕
Really sounds to me like "I used some secret scientific fact that some famous person told me about, so you've got to believe it, and sorry but you can't check it, it's private" 😕
March 5, 2025 at 9:26 AM
Can somebody explain to me what the heck is the usefulness of referencing a "private communication" in a paper?
Really sounds to me like "I used some secret scientific fact that some famous person told me about, so you've got to believe it, and sorry but you can't check it, it's private" 😕
Really sounds to me like "I used some secret scientific fact that some famous person told me about, so you've got to believe it, and sorry but you can't check it, it's private" 😕
Looking forward to this!
Thanks @danclery.bsky.social for the nice interview!
Modest telescope with big plans, SPHEREx will probe cosmic ‘inflation’ after Big Bang www.science.org/content/arti...
#cosmology #inflation #SPHEREx 🧪⚛️
Thanks @danclery.bsky.social for the nice interview!
Modest telescope with big plans, SPHEREx will probe cosmic ‘inflation’ after Big Bang www.science.org/content/arti...
#cosmology #inflation #SPHEREx 🧪⚛️
Modest telescope with big plans, SPHEREx will probe cosmic ‘inflation’ after Big Bang
Spacecraft with gather and analyze infrared light in new ways to explain why our universe is “boring”
www.science.org
February 23, 2025 at 9:47 AM
Looking forward to this!
Thanks @danclery.bsky.social for the nice interview!
Modest telescope with big plans, SPHEREx will probe cosmic ‘inflation’ after Big Bang www.science.org/content/arti...
#cosmology #inflation #SPHEREx 🧪⚛️
Thanks @danclery.bsky.social for the nice interview!
Modest telescope with big plans, SPHEREx will probe cosmic ‘inflation’ after Big Bang www.science.org/content/arti...
#cosmology #inflation #SPHEREx 🧪⚛️
The NSF budget reduced by two thirds. Incredible.
Public funding of research in the US will die if people don't react quickly.
www.science.org/content/arti...
Public funding of research in the US will die if people don't react quickly.
www.science.org/content/arti...
‘My boss was crying.’ NSF confronts potentially massive layoffs and budget cuts
Trump could propose slashing agency’s budget by two-thirds
www.science.org
February 22, 2025 at 10:09 AM
The NSF budget reduced by two thirds. Incredible.
Public funding of research in the US will die if people don't react quickly.
www.science.org/content/arti...
Public funding of research in the US will die if people don't react quickly.
www.science.org/content/arti...
It is starting. The US government idea of limiting to 15% indirect costs of research taken on research grants leads some universities to stop hiring PhD students.
This has to stop very quickly. It won't unless the American people protests or strikes as a whole.
www.wesa.fm/health-scien...
This has to stop very quickly. It won't unless the American people protests or strikes as a whole.
www.wesa.fm/health-scien...
The University of Pittsburgh pauses its Ph.D. admissions process amid research funding uncertainty
A spokesperson for the University told WESA Friday that the school has "temporarily paused additional Ph.D. offers of admission," while Pitt works to understand how proposed federal funding cuts could...
www.wesa.fm
February 22, 2025 at 9:47 AM
It is starting. The US government idea of limiting to 15% indirect costs of research taken on research grants leads some universities to stop hiring PhD students.
This has to stop very quickly. It won't unless the American people protests or strikes as a whole.
www.wesa.fm/health-scien...
This has to stop very quickly. It won't unless the American people protests or strikes as a whole.
www.wesa.fm/health-scien...
Based outside the UK and interested in a postdoc at King's College London in numerical GR/cosmology?
Contact Eugene @tukohbin.bsky.social!
Contact Eugene @tukohbin.bsky.social!
If anyone (or knows anyone) who is interested in applying for the Newton Fellowship with KCL/me (2y, up to 280k), email/DM me! For early career non-UK based scientists. There's an internal selection with deadline of Feb 24, so let me know by next Wed 19th.
royalsociety.org/grants/newto...
royalsociety.org/grants/newto...
Newton International Fellowships | Royal Society
This fellowship is for non-UK scientists who are at an early stage of their research career and wish to conduct research in the UK.
royalsociety.org
February 20, 2025 at 11:51 PM
Based outside the UK and interested in a postdoc at King's College London in numerical GR/cosmology?
Contact Eugene @tukohbin.bsky.social!
Contact Eugene @tukohbin.bsky.social!
Reposted by Lucien Heurtier
Unexpected epochs of stillness that punctuate the cosmic timeline could offer a natural explanation for dark matter and many other unsolved astronomical mysteries.
How cosmic stasis may drastically rewrite the history of the universe
www.newscientist.com
February 15, 2025 at 12:33 PM
Unexpected epochs of stillness that punctuate the cosmic timeline could offer a natural explanation for dark matter and many other unsolved astronomical mysteries.
Reposted by Lucien Heurtier
In space, no-one can hear you scream – is it on pause?⏸️
In @newscientist.com, @lucienheurtier.bsky.social shares how the history of the cosmos could be defined by stillness, potentially turning the universe's history on it’s head🌌
https://buff.ly/4aVmg7o #Physics #Astronomy
In @newscientist.com, @lucienheurtier.bsky.social shares how the history of the cosmos could be defined by stillness, potentially turning the universe's history on it’s head🌌
https://buff.ly/4aVmg7o #Physics #Astronomy
February 13, 2025 at 2:07 PM
In space, no-one can hear you scream – is it on pause?⏸️
In @newscientist.com, @lucienheurtier.bsky.social shares how the history of the cosmos could be defined by stillness, potentially turning the universe's history on it’s head🌌
https://buff.ly/4aVmg7o #Physics #Astronomy
In @newscientist.com, @lucienheurtier.bsky.social shares how the history of the cosmos could be defined by stillness, potentially turning the universe's history on it’s head🌌
https://buff.ly/4aVmg7o #Physics #Astronomy
In 2020, I discovered with my US collaborators a new paradigm for #cosmology and #particle #physics that we named "Cosmic Stasis".
We then published several works investigating the many implications of such a discovery.
This was featured this week in the New Scientist!
Article by Miriam Frankel.🧪
We then published several works investigating the many implications of such a discovery.
This was featured this week in the New Scientist!
Article by Miriam Frankel.🧪
Unexpected epochs of stillness that punctuate the cosmic timeline could offer a natural explanation for dark matter and many other unsolved astronomical mysteries www.newscientist.com/article/mg26...
How cosmic stasis may drastically rewrite the history of the universe
Unexpected epochs of stillness that punctuate the cosmic timeline could offer a natural explanation for dark matter and many other unsolved astronomical mysteries
www.newscientist.com
February 13, 2025 at 11:53 AM
In 2020, I discovered with my US collaborators a new paradigm for #cosmology and #particle #physics that we named "Cosmic Stasis".
We then published several works investigating the many implications of such a discovery.
This was featured this week in the New Scientist!
Article by Miriam Frankel.🧪
We then published several works investigating the many implications of such a discovery.
This was featured this week in the New Scientist!
Article by Miriam Frankel.🧪
UK-APP is born! 🧪
This new conference series dedicated to astroparticle physics phenomenology will take place for its first edition at King's Collefe London @kingsnmes.bsky.social on June 2nd 2025!
Put it on your calendar and register!
indico.global/event/13955/...
This new conference series dedicated to astroparticle physics phenomenology will take place for its first edition at King's Collefe London @kingsnmes.bsky.social on June 2nd 2025!
Put it on your calendar and register!
indico.global/event/13955/...
UK-APP and OWAN 25 conferences
On June 2nd and 3rd 2025, King's College London will jointly host two conferences back to back: The semi-annual UK-APP conference and the OWAN 25 conference (see descriptions below). The two events ar...
indico.global
February 6, 2025 at 12:37 PM
UK-APP is born! 🧪
This new conference series dedicated to astroparticle physics phenomenology will take place for its first edition at King's Collefe London @kingsnmes.bsky.social on June 2nd 2025!
Put it on your calendar and register!
indico.global/event/13955/...
This new conference series dedicated to astroparticle physics phenomenology will take place for its first edition at King's Collefe London @kingsnmes.bsky.social on June 2nd 2025!
Put it on your calendar and register!
indico.global/event/13955/...
Reposted by Lucien Heurtier
Primordial Black Hole Hot Spots and Nucleosynthesis. Clelia Altomonte et. al. https://arxiv.org/abs/2501.05531
January 13, 2025 at 10:41 PM
Primordial Black Hole Hot Spots and Nucleosynthesis. Clelia Altomonte et. al. https://arxiv.org/abs/2501.05531
It's paper day! With my great collaborators C. Altomonte @cleliaaltomonte.bsky.social & M. Fairbairn @malcfairbairn.bsky.social, we explored how the formation of hot spots around Primordial Black Holes affect Big-Bang Nucleosynthesis constraints on their abundance. Thread 🧵👇 arxiv.org/abs/2501.05531
Primordial Black Hole Hot Spots and Nucleosynthesis
Upon their evaporation via Hawking radiation, primordial black holes (PBHs) may deposit energy in the ambient plasma on scales smaller than the typical distance between two black holes, leading to the...
arxiv.org
January 13, 2025 at 11:06 AM
It's paper day! With my great collaborators C. Altomonte @cleliaaltomonte.bsky.social & M. Fairbairn @malcfairbairn.bsky.social, we explored how the formation of hot spots around Primordial Black Holes affect Big-Bang Nucleosynthesis constraints on their abundance. Thread 🧵👇 arxiv.org/abs/2501.05531
My windshield this morning. Nature is beautiful ❤️
January 12, 2025 at 10:51 AM
My windshield this morning. Nature is beautiful ❤️
When Amazon reminds me to do a Raclette this winter 🧀😂
January 8, 2025 at 3:01 PM
When Amazon reminds me to do a Raclette this winter 🧀😂
This past year was full of happiness but also challenges. This new one promises to have its load of challenges too.
People: "Happy new year!"
Me: [Deep breath] "Ok let's go!" 💪
#nevergiveup
People: "Happy new year!"
Me: [Deep breath] "Ok let's go!" 💪
#nevergiveup
January 1, 2025 at 11:37 PM
This past year was full of happiness but also challenges. This new one promises to have its load of challenges too.
People: "Happy new year!"
Me: [Deep breath] "Ok let's go!" 💪
#nevergiveup
People: "Happy new year!"
Me: [Deep breath] "Ok let's go!" 💪
#nevergiveup
This means a lot to me. Support is the thing I believe is the most essential in a student's journey, and I feel so blessed that the support I provide to my peers had a positive impact at KCL @kingsnmes.bsky.social
Thanks to all the students who nominated me 🙏
www.kcl.ac.uk/news/kings-s...
Thanks to all the students who nominated me 🙏
www.kcl.ac.uk/news/kings-s...
December 20, 2024 at 12:55 PM
This means a lot to me. Support is the thing I believe is the most essential in a student's journey, and I feel so blessed that the support I provide to my peers had a positive impact at KCL @kingsnmes.bsky.social
Thanks to all the students who nominated me 🙏
www.kcl.ac.uk/news/kings-s...
Thanks to all the students who nominated me 🙏
www.kcl.ac.uk/news/kings-s...