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Héctor Gil Marín @cosmonautico.bsky.social · Aug 29

icc.ub.edu/news/desi-co...

DESI Collaboration to receive 2026 Berkeley Prize awarded by the American Astronomical Society | ICCUB

The Dark Energy Spectroscopic Instrument (DESI) collaboration will receive the 2026 Lancelot M.

icc.ub.edu

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Héctor Gil Marín @cosmonautico.bsky.social · May 20

Demà 21 de maig a les 19h al centre cívic Sarrià!

Héctor Gil Marín @cosmonautico.bsky.social · May 11

En dues setmanes participaré al event Pint of Science 2025 🍺🪐, será dimecres 21 al centre cívic Sarrià (Kasa Hanaka Sarrià) i parlaré sobre el costat fosc de l'univers (aka Dark Energy i Dark Matter) a partir de les 19h.

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Reposted by Héctor Gil Marín

ICCUBDivulga @iccubdivulga.bsky.social · May 16

🎉🍻Torna el @pintofscience.es a Barcelona!

Investigadors de l’ #ICCUB ens parlaran de neutrins, energia fosca i matèria fosca, els grans enigmes que encara desafien la ciència!⚛️💫

Gaudeix-ne en un ambient relaxat i divertit!
🔗 bit.ly/4dllQs8 @delbuitaltot.bsky.social @cosmonautico.bsky.social

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Reposted by Héctor Gil Marín

Toni Bertólez @delbuitaltot.bsky.social · May 16

Així farem 🫡
La meva xerrada i la del @cosmonautico.bsky.social encaixen genial, així que teniu doble pla per a la setmana! 👀

ICCUBDivulga @iccubdivulga.bsky.social · May 16

🎉🍻Torna el @pintofscience.es a Barcelona!

Investigadors de l’ #ICCUB ens parlaran de neutrins, energia fosca i matèria fosca, els grans enigmes que encara desafien la ciència!⚛️💫

Gaudeix-ne en un ambient relaxat i divertit!
🔗 bit.ly/4dllQs8 @delbuitaltot.bsky.social @cosmonautico.bsky.social

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Héctor Gil Marín @cosmonautico.bsky.social · May 11

En dues setmanes participaré al event Pint of Science 2025 🍺🪐, será dimecres 21 al centre cívic Sarrià (Kasa Hanaka Sarrià) i parlaré sobre el costat fosc de l'univers (aka Dark Energy i Dark Matter) a partir de les 19h.

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Héctor Gil Marín @cosmonautico.bsky.social · Mar 26

#montoya 🤣

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Héctor Gil Marín @cosmonautico.bsky.social · Mar 20

☄️Today at the @icc-ub.bsky.social at Uni Barcelona we had one of the first presentations of the @desisurvey.bsky.social BAO DR2 results!🔭🧪
You can check it out on Youtube!
youtu.be/tuDzhR1SVDg?...

Presentation of the DESI DR2 BAO Results at ICCUB - Héctor Gil Marín

YouTube video by Cosmology at home

youtu.be

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Héctor Gil Marín @cosmonautico.bsky.social · Mar 20

LCDM doesn't seem that robust anymore.
Is it a problem with the model? Is it a problem with the data?
Why does LCDM seem to break in this funny degeneration precisely crossing LCDM?
Interesting times ahead!! Looking forward to new @desisurvey.bsky.social releases.
Credit: @clairelamman.bsky.social

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Héctor Gil Marín @cosmonautico.bsky.social · Mar 20

7. And finally, neutrinos. Within LCDM the neutrino bound at 95% is on <0.064 eV, but without a peak expected on the negative neutrino masses. Within wowaCDM the 95% bound is on <0.163 eV, but the peak is on the positive side.

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Héctor Gil Marín @cosmonautico.bsky.social · Mar 20

6. When adding the SNe, the tension rises to 2.8σ if we consider Pantheon+, 3.8σ for Union3, and 4.2σ for DES. However, this tension can be relaxed if z<0.1 SNe (the less homogeneous ones for the DES case) are removed.

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Héctor Gil Marín @cosmonautico.bsky.social · Mar 20

5. DESI with the full CMB (w lensing) is in tension with LCDM at 3.1σ when we allow w0-wa to vary. This can be reduced to 2.4σ if lensing and other late-time effects are excluded.

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Héctor Gil Marín @cosmonautico.bsky.social · Mar 20

3. As expected, the same H0 tension between direct measurements and inverse-distance ladder (via sound horizon scale) calibration. But....
4. We also find mild-to-strong discrepancy on the Ωm between DESI-BAO and the uncalibrated SNe (depending on the SNe sample)

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Héctor Gil Marín @cosmonautico.bsky.social · Mar 20

🔊 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.

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Héctor Gil Marín @cosmonautico.bsky.social · Mar 20

In this contour, DESY5 means the SNe from DES, not the 3x2pt DES (that would be Y3, as there are no Y5 yet, as far as I know). The tension with LCDM in this plot is 4.2 sigma. Excluding any SNe, but keeping the full CMB signal (with lensing included), makes the tension 3.1 sigma.

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Héctor Gil Marín @cosmonautico.bsky.social · Mar 19

Bueno, de DESI es más bien mañana si vives en este lado del planeta 🔭

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Héctor Gil Marín @cosmonautico.bsky.social · Mar 19

📢In less than 24h, @desisurvey.bsky.social will present the 3D BAO analysis of its first 3yr of data (DR2), the BAO analysis of the largest sample of galaxies ever!!! And we will release all DR1 catalogues (1yr of data) as well. You will find all the details on arXiv and SM channels. Stay tuned. 🎶

DESI Survey @desisurvey.bsky.social · Mar 18

At the same time, we’re also releasing exciting new results, including BAO measurements from galaxies, quasars, and Lyman-alpha forests.

🔗 Info about these results will be available on the DESI website: desi.lbl.gov

Dark Energy Spectroscopic Instrument (DESI)

desi.lbl.gov

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Héctor Gil Marín @cosmonautico.bsky.social · Mar 14

You can read more about it in arxiv.org/abs/2503.09714, and stay tuned for fa ollow-up paper on the cosmological interpretation of these results in the light of different cosmology models, and in combination with other datasets!

Full-Shape analysis of the power spectrum and bispectrum of DESI DR1 LRG and QSO samples

We present the first joint analysis of the power spectrum and bispectrum using the Data Release 1 (DR1) of the Dark Energy Spectroscopic Instrument (DESI), focusing on Luminous Red Galaxies (LRGs) and...

arxiv.org

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Héctor Gil Marín @cosmonautico.bsky.social · Mar 14

A lot of effort has been spent into determining potential systematics. This has only been possible thanks to the invaluable help of the DESI team. Not only for the production of this excellent dataset, but also the many resources in the type of realistic mocks and pipelines.

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Héctor Gil Marín @cosmonautico.bsky.social · Mar 14

Thanks to this extra information brought by the bispectrum signal, we can constrain the isotropic dilation scale, the Alcock-Paczynski parameter, the growth of structure and the shape of the power spectrum with better precision than with the recent power spectrum only analysis. 📐

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Héctor Gil Marín @cosmonautico.bsky.social · Mar 14

🥁Paper Day! Here goes the first bispectrum analysis of the @desisurvey.bsky.social DR1 LRG and QSO data, led by my PhD student Sergi Novell at @icc-ub.bsky.social. In combination with the power spectrum multipoles we measure 150 triangle configurations corresponding to a total volume of 13.1 Gpc3

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Héctor Gil Marín @cosmonautico.bsky.social · Feb 23

Dimecres 26 de Febrer a les 19h parlaré sobre la matèria i l'energia fosca i el paper dels cartografiats de galàxies en la cosmologia actual.
📍Agrupació Astronómica de sabadell.
🕖 19h. Entrada lliure fins a completar l'aforament.
🗣 Idioma castellà.

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Reposted by Héctor Gil Marín

Sean Carroll @seanmcarroll.bsky.social · Feb 7

The US government has been turned over to a group of extraordinarily ignorant people, and they are working to destroy science in this country. Cutting over half the NSF budget would save < 0.1% of the federal budget, but do incalculable harm. Simply heartbreaking.

arstechnica.com/science/2025...

White House budget proposal could shatter the National Science Foundation

“This kind of cut would kill American science and boost China.”…

arstechnica.com

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Reposted by Héctor Gil Marín

El Espectro 👻 🎃 @telescoper.bsky.social · Dec 12

Cosmology Talks: Recent DESI Power Spectrum Results

Some weeks ago I posted an item about recent results that have emerged from the DESI (Dark Energy Spectroscopic Instrument) Collaboration. I have been a bit busy since then but I just saw that there is one of those Cosmology Talks about these…

Cosmology Talks: Recent DESI Power Spectrum Results

Some weeks ago I posted an item about recent results that have emerged from the DESI (Dark Energy Spectroscopic Instrument) Collaboration. I have been a bit busy since then but I just saw that there is one of those Cosmology Talks about these results which I thought I would pass on. The contributors are Arnaud de Mattia, Hector Gil-Marín and Pauline Zarrouk and they are talking about the analsysis they have done using the "full shape" of the galaxy power spectrum. It's quite a long video, but very illuminating.

telescoper.blog

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Héctor Gil Marín @cosmonautico.bsky.social · Dec 5

Maybe I am missing something, but a few months before (arxiv.org/pdf/1707.06547) this paper already combined BAO+BBN to obtain H0=67.81±1.25 km/s/Mpc. Once galaxy and Lya BAO are included there is no longer a strong degeneracy on H0-Om plane, and WL data doesn't add much, as the DES col acknowledges

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Reposted by Héctor Gil Marín

Institute of Cosmos Sciences of the University of Barcelona @icc-ub.bsky.social · Dec 5

🏅Congratulations to our researcher Licia Verde, who yesterday received the 2024 Medal of the #RSEF-FundacionBBVA!

🌌This prestigious award recognizes her groundbreaking contributions to cosmology, dark matter, and the universe's expansion

👉 icc.ub.edu/news/licia-v...

@ub.edu @espai.media

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