[Astro] [CAPT] CAPT Weekly Bulletin (w/c 06-10-25)

[Ella Batchelor (staff)]

Monday 6th October at 3pm, A113 CAPT – Theoretical Physics Student Seminar

Trevor Cheung

Are the Feynman rules you learnt still correct?



Tuesdays at 11am, CAPT Foyer – Astro Coffee



Tuesday 7th October at 1pm, A113 CAPT – Particle Cosmology and Gravity Seminar

William Giarè (Sheffield)

Lost Beyond ΛCDM


As cosmological observations reach unprecedented precision, the standard ΛCDM model is facing mounting pressure on multiple fronts. The well-known Hubble tension — a persistent  discrepancy between early- and late-universe determinations of the Hubble constant — challenges the foundations of our baseline paradigm. At the same time, recent Baryon Acoustic Oscillation measurements from DESI suggest bounds on the sum of neutrino masses that increasingly conflict with lower limits from particle physics, assuming standard cosmology. Extensions to the dark energy sector, particularly evolving dark energy models, can alleviate the neutrino mass tension and even appear to disfavor a cosmological constant at ~3-4σ. Yet these scenarios generally fail to address the Hubble tension. Conversely, both early- and late-time solutions proposed for the Hubble tension often drive the neutrino mass toward unrealistically small values, worsening the conflict with particle physics. This raises a natural question: is a coherent framework capable of reconciling all datasets still within reach, or is the cosmological blanket simply too short, such that pulling to cover one discrepancy inevitably leaves another exposed? In this talk, I will explore the web of tensions currently plaguing modern cosmology, and outline possible pathways into the beyond-ΛCDM landscape.

Link to join:  https://teams.microsoft.com/l/meetup-join/19%3ameeting_OGM3OTk5NzQtZWEwZS00ZmUyLTk3MGUtZjFhY2M5OTU2MjI1%40thread.v2/0?context=%7b%22Tid%22%3a%2267bda7ee-fd80-41ef-ac91-358418290a1e%22%2c%22Oid%22%3a%22f3250584-4b5f-48fa-a897-08e77f2246b7%22%7d

---

Wednesday 8th October at 11am, A113 CAPT – CAPT Coding Club



Wednesday 8th October at 3.45pm, A113 CAPT – Astronomy Weekly Seminar
Departmental Jamboree



---

Thursday 9th October at 1pm, A113 CAPT – Astronomy Lunch Talk

Jesse Golden-Marx
The Metallicity of the ICL: A Euclid Q1 Story

Colour provides key information for constraining the stellar population of the intracluster light (ICL), the diffuse light within galaxy clusters. Using the Euclid Q1 photometry for 174 DES-redMaPPer galaxy clusters (within the Q1 footprint) over the redshift range 0.1 < z < 0.75, we derive radial colour profiles of the brightest central galaxy (BCG) and ICL. Using elliptical annuli, we detect a colour gradient, such that the ICL is bluer than the BCG. By stacking these profiles, we can extend this gradient out to 600kpc. Using stellar population synthesis models, we find that near infrared colours are sensitive to metallicity, not age. Thus, we measure a metallicity gradient in the BCG+ICL out to 600kpc for the first time. We find that the metallicity of the BCG, which moderately evolves with redshift, is super-solar [log10 (Z/Zsun) > 0.2], while the ICL is metal-poor [log10(Z/Zsun)\sim -0.5 to -1.0], placing the first statistical constraint on the metallicity of the ICL as a population out to large radii. These results support our current understanding of BCG and ICL formation: BCGs form predominantly through mergers with massive galaxies or the cores of satellite galaxies, while the ICL grows via the tidal stripping of lower metallicity stars from the outskirts of massive satellite galaxies.



Thursday 9th October at 3pm, A113 CAPT – Particle Cosmology Journal Club
---
Fridays at 4pm, CAPT Foyer – CAPT Cakes
---
If you have any events/visitors you would like included in next week’s bulletin, please let me know.


Best wishes

Ella

Ella Batchelor (she/her)
Administrator

School of Physics & Astronomy

University of Nottingham
A112a Centre for Astronomy & Particle Theory
University Park
Nottingham, NG7 2RD

+44 (0) 115 74 86778 |  nottingham.ac.uk<http://nottingham.ac.uk/>

[cid:image001.png at 01DC369A.F50AC720]

Follow us
facebook.com/uniofnottingham<http://facebook.com/TheUniofNottingham>
twitter.com/uniofnottingham<http://twitter.com/UniofNottingham>
youtube.com/nottmuniversity<http://youtube.com/nottmuniversity>
instagram.com/uniofnottingham<http://instagram.com/uniofnottingham>
linkedin.com/company/university-of-nottingham<http://linkedin.com/company/university-of-nottingham>

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.nottingham.ac.uk/pipermail/astro/attachments/20251006/537df081/attachment-0001.htm>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image001.png
Type: image/png
Size: 190221 bytes
Desc: image001.png
URL: <http://lists.nottingham.ac.uk/pipermail/astro/attachments/20251006/537df081/attachment-0001.png>
-------------- next part --------------
_______________________________________________
CAPT mailing list
CAPT at lists.nottingham.ac.uk
https://lists.nottingham.ac.uk/mailman/listinfo/capt