Today we have the pleasure of hosting Lei Zu (祖磊), currently a postdoc at the National Centre for Nuclear Research (NCBJ) in Warsaw, and an expert on various signatures of dark sector physics in astrophysical and cosmological observables. Lei delivered a very nice seminar by the title of “Exploring dark matter non-gravitational interactions through weak lensing”. Welcome Lei!
Visit by Marc Henneaux
For the next two days we have the pleasure of hosting Prof. Marc Henneaux, a renown theoretical physicist from Collège de France. Marc is here as visiting chair within the University of Trento-College de France visiting chair program (similarly to Prof. Françoise Combes last year). He will be delivering two seminars by the title of “Ultrarelativistic Limits of Gravity and Carroll Group” and a colloquium by the title of “Asymptotic Symmetries in Gauge Theories with Emphasis on Gravity”. Welcome Marc!
Expressions of interest for Marie Skłodowska-Curie Fellowships
I invite expressions of interest for Marie Skłodowska-Curie Fellowships in my group, for the call which will open later this year, to start roughly in Fall 2026. If you are interested, please send me an expression of interest following the indications provided in the INSPIRE job ad, with material to be sent to this AJO eDelivery link by March 31, 2025. As explained in detail the job ad (please read it carefully), the cover letter and sketch of possible research project are particularly important and will play a key role in my evaluation of the expressions of interest, so do pay particular attention to those. Please note that I can support at most one highly qualified candidate. If you have questions, send me an email using the subject line indicated in the job ad.
Post-DESI neutrino cosmology paper published in JCAP!
My paper with Jun-Qian Jiang, William Giarè, Stefano Gariazzo, Maria Giovanna Dainotti, Eleonora Di Valentino, Olga Mena, Davide Pedrotti, and Simony Santos da Costa, where we investigate the status of (positive) neutrino mass cosmology after the latest DESI measurements (see this earlier news item), has now officially been published in JCAP! The full bibliographic coordinates for the paper are JCAP 2501 (2025) 153. Here is the link to the paper (which is published Open Access).
Primordial regular black holes papers published in PRD!
My two papers on primordial regular BHs with Marco Calzà and Davide Pedrotti (see these two earlier news items: part 1 and part 2), where we characterize non-singular primordial BHs as DM candidates, have now officially been published in PRD! The full bibliographic coordinates for the papers are Phys. Rev. D 111 (2025) 024009 and Phys. Rev. D 111 (2025) 042010. Here and here are the links to the papers.
Hubble tension, Ωm, and ωc paper published in PRD!
My paper with Davide Pedrotti, Jun-Qian Jiang, Luis Escamilla, and Simony Santos da Costa, where we discuss the multidimensionality of the Hubble tension and the roles of Ωm and ωc (see this earlier news item), has now officially been published in PRD! The full bibliographic coordinates for the paper are Phys. Rev. D 111 (2025) 023506. Here is the link to the paper.
Post-DESI neutrino cosmology paper accepted in JCAP!
My paper with Jun-Qian Jiang, William Giarè, Stefano Gariazzo, Maria Giovanna Dainotti, Eleonora Di Valentino, Olga Mena, Davide Pedrotti, and Simony Santos da Costa, where we investigate the status of (positive) neutrino mass cosmology after the latest DESI measurements (see this earlier news item), has been accepted for publication in JCAP! The paper has undergone has a substantial revision, which resulted in the addition of several appendices clarifying various technical aspects of the analysis (e.g. cosmology-internal tension, impact of PR4 likelihoods, and H0 versus MB prior among others), as well as an additional useful plot, and useful discussions on the neutrino mass ordering: however, the main results are unaltered, and are now more robust. You can read the preprint version of the paper on arXiv: 2407.18047.
Stochastic gravitational wave background from cosmologically coupled black holes paper published in Scientific Reports!
My paper with Marco Calzà, Francesco Gianesello, and Max Rinaldi, where we study the stochastic gravitational wave background signal resulting from inspiraling cosmologically coupled BHs (see this earlier news item), has now officially been published in Scientific Reports (making this my third proper Nature publication)! The full bibliographic coordinates for the paper are Sci. Rep. 14 (2024) 31296. Here is the link to the paper (which is published Open Access).
FLAG Christmas meeting
Today and tomorrow Trento is hosting the usual Christmas meeting of the INFN FLAG iniziativa specifica, and on the occasion I will be giving a talk on “Five brief lessons on the Hubble tension” (whose slides you can find here). The meeting is typically held in Bologna just before Christmas, but this year it takes place in Trento under exceptional circumstances. Looking forward to seeing many familiar faces again (including our high-profile guest speaker and former Trento student Marco Peloso!), and to a nice dinner at Trattoria Piedicastello!
Marco Bella joins my group!
Today Marco Bella officially joins my group, to do his Master’s thesis under my supervision. We plan to work out, in a way as model-agnostic as possible, the pre-recombination ingredients required to solve the Hubble tension. Welcome Marco, and I’m looking forward to our work together!
Non-parametric expansion history reconstruction paper published in PRD!
My paper with Jun-Qian Jiang, Davide Pedrotti, and Simony Santos da Costa, where we perform a non-parametric reconstruction of the late-time expansion history in light of DESI BAO data (see this earlier news item), has now officially been published in PRD! The full bibliographic coordinates for the paper are Phys. Rev. D 110 (2024) 123519. Here is the link to the paper.
Hubble tension, Ωm, and ωc paper accepted in PRD!
My paper with Davide Pedrotti, Jun-Qian Jiang, Luis Escamilla, and Simony Santos da Costa, where we discuss the multidimensionality of the Hubble tension and the roles of Ωm and ωc (see this earlier news item), has been accepted for publication in PRD! There were extremely minor revisions compared to the earlier version, which have resulted in a clearer discussion of the novel aspects and the domain of applicability of our results. You can read the preprint version of the paper on arXiv: 2408.04530.
Stochastic gravitational wave background from cosmologically coupled black holes paper accepted in Scientific Reports!
My paper with Marco Calzà, Francesco Gianesello, and Max Rinaldi (proudly 100% made within the Theoretical Gravitation and Cosmology Group led by myself and Max!) , where we study the stochastic gravitational wave background signal resulting from inspiraling cosmologically coupled BHs (see this earlier news item), has been accepted for publication in Scientific Reports, part of the Nature Portfolio collection of journals (therefore making this my third proper Nature publication)! With respect to the earlier version we have slightly changed the title and explained the content of Fig. 2 much more clearly, but the main message of the paper is otherwise unchanged. You can read the preprint version of the paper on arXiv: 2409.01801.
Primordial regular black holes papers accepted in PRD!
Extremely good news today as my two earlier papers on primordial regular BHs with Marco Calzà and Davide Pedrotti (see these two earlier news items: part 1 and part 2), where we characterize non-singular primordial BHs as DM candidates, have both been accepted for publication in PRD! There have been a few changes with respect to the earlier versions (slight changes to the titles, discussions on the time evolution of these BHs added, and a few minor additions), but our main messages are unaltered. You can read the preprint versions of the papers on arXiv: 2409.02804 and 2409.02807.
Advanced Science news coverage for EHT and mimetic gravity paper
Advanced Science News interviewed me about our paper (published in Scientific Reports) showing that EHT observations rule out mimetic gravity. You can find their nice piece below:
www.advancedsciencenews.com/black-hole-images-deliver-a-deathblow-to-alternative-theory-of-gravity/
Enjoy the read!
Non-parametric expansion history reconstruction paper accepted in PRD!
My paper with Jun-Qian Jiang, Davide Pedrotti, and Simony Santos da Costa (first one entirely produced within my group), where we perform a non-parametric reconstruction of the late-time expansion history in light of DESI BAO data (see this earlier news item), has been accepted for publication in PRD! Compared to the earlier version, there have been minor changes to the plots and title, but our main results are unaltered. You can read the preprint version of the paper on arXiv: 2408.02365.
EHT and mimetic gravity paper published in Scientific Reports!
My paper with Mohsen Khodadi and Javad Firouzjaee, where we show that the EHT observations of M87* and Sgr A* rule out the baseline version of mimetic gravity (see this earlier news item), has now officially been published in Scientific Reports (making this my second proper Nature publication)! The full bibliographic coordinates for the paper are Sci. Rep. 14 (2024) 26932. Here is the link to the paper (which is published Open Access).
ISGC seminar
Today I delivered a seminar in the Intercontinental Seminars on Gravity and Cosmology series by the title of Five brief lessons on the Hubble tension (slides here). The seminar was recorded and posted on YouTube, here is the link. I highly recommend this seminar series!
EHT and mimetic gravity paper accepted in Scientific Reports!
My paper with Mohsen Khodadi and Javad Firouzjaee, where we show that the EHT observations of M87* and Sgr A* rule out the baseline version of mimetic gravity (see this earlier news item), has been accepted for publication in Scientific Reports, part of the Nature Portfolio collection of journals (therefore making this my second proper Nature publication)! The most significant addition compared to the earlier version is a new figure with examples of null geodesics in the space-times we studied, which shows in a very clear way why their shadow properties are pathological. You can read the preprint version of the paper on arXiv: 2408.03241.
Visit by Davide Racco and Flaminia Giacomini
For the next days we have the pleasure of hosting Davide Racco and Flaminia Giacomini, who are visiting us from Zurich (respectively from the University of Zurich+ETH, and ETH). Both are very well-known researchers with interests at the intersection of particle physics and cosmology (Davide) and at the interface between quantum theory/quantum information and gravity (Flaminia). They will be giving seminars by the titles of “Insights on fundamental physics from Gravitational Wave backgrounds” and “Quantum effects in gravity from a delocalised quantum source” . Welcome Davide and Flaminia!
