My paper with Misba Afrin and Sushant Ghosh on Loop Quantum Gravity and the shadow of Sgr A*, which I previously reported on in an earlier news item, has now officially been published in ApJ! The full bibliographic coordinates for the paper are Astrophys. J. 944 (2023) 149. Here is the link to the paper (which is published Open Access).
Physics Frontiers podcast episode on the primordial graviton background
In early December 2022 I had the pleasure to be interviewed by Jim Rantschler for his well-known Physics Frontiers podcast, where we talked about my primordial graviton background paper, other stuff in physics, and life in general. The podcast episode is now officially out, and you can find it here, or if you prefer on Spotify. There will also be an associated Random Questions video interview which will appear on the podcast’s YouTube channel in the coming weeks. It was great fun chatting to Jim, and I hope you enjoy the interview!
Early dark energy and massive neutrinos paper published in MNRAS!
My paper with Alex Reeves, Laura Herold, Blake Sherwin, and Elisa Ferreira on early dark energy and massive neutrinos, which I previously reported on in an earlier news item, has now officially been published in MNRAS! The full bibliographic coordinates for the paper are Mon. Not. Roy. Astron. Soc. 520 (2023) 3688. Here is the link to the paper (which is published Open Access).
Visit by Luca Visinelli
And we have more visitors: Luca Visinelli from Shanghai Jiao Tong University will also be here for the next two days! Luca is a close collaborator of mine (he is in fact the person with whom I have the most papers in common, with the reverse also holding), and is a very well-known scientist with broad research interests spanning dark matter, dark energy, and black holes. We’ll take the opportunity to catch up on the many projects we have ongoing, and Luca will also deliver a seminar by the title of “The interplay of primordial black holes and particle dark matter”. To celebrate Luca’s birthday, we enjoyed a nice dinner together with Anjan (see below) at La Grotta, one of my favorite restaurants in Trento. It’s very nice to have people travelling and visiting once more, it was definitely something I had missed during the pandemic!
Universe special issue (successfully) closed
The Universe Special Issue “Dark Matter and Dark Energy: Particle Physics, Cosmology, and Experimental Searches” I guest edited together with Eleonora Di Valentino, Alessandro Melchiorri, Olga Mena, and Luca Visinelli, has officially closed today. I am happy say that it was a great success: we published 21 papers, some of which either already of very high impact, or whose impact I expect will be very high. Some highlights of the Special Issue include the classic Mazur-Mottola 2001 gravastar paper (with nearly 1000 citations!), which had previously remained unpublished for over two decades, with a similar fate for the classic Benaoum 2002 modified Chaplygin gas paper, and finally a nice review on dark radiation by Archidiacono and Gariazzo. It was a great fun to work on this Special Issue, and thanks to all the authors for their very nice contributions!
Visit by Anjan Sen
I’m delighted to host my first official visito here in Trento, Anjan Sen from Jamia Millia Islamia! Anjan is a well-known cosmologist whose recent research interests include the nature of dark energy and cosmological tensions. We have never met in person but have shared many interesting email discussions, and more generally share many common interests among which the cosmological consequences of a negative cosmological constant. Anjan will be visiting us for a week and a half, and will also deliver a seminar by the title of “Story of the Dark Universe”. Looking forward to many interesting discussions!
UniVersum IV
Really excited to be attending UniVersum IV, the fourth edition of the UniVersum series of cosmology meetings, roughly the Italian equivalent of UKCosmo for the UK, or IberiCos for Spain-Portugal. This year’s edition is held, excitingly, in Trento! It also happens to be my first in-person conference after the pandemic. I will be giving a keynote talk on “Cosmic acceleration: now, then, and back then”, whose slides you can find here. Looking forward to lots of interesting discussions!
Associated to TIFPA-INFN
As of today I’m officially associated to INFN, the Italian National Institute for Nuclear Physics. I’m associated through our local TIFPA center, which stands for “Trento Institute for Fundamental Physics and Applications”. In particular, I’ll be a member of the FLAG Iniziativa Specifica, which stands for “Quantum Fields in Gravity, Cosmology and Black Holes”, and focuses on a number of themes which include early-Universe cosmology and black hole physics. Looking forward to many interesting discussions which will come out of this, especially from FLAG!
Early dark energy and massive neutrinos paper accepted in MNRAS!
My paper with Alex Reeves, Laura Herold, Blake Sherwin, and Elisa Ferreira (a very international collaboration, spanning 6 different countries - Switzerland, Germany, Italy, UK, Japan, and Brazil!), where we study whether a cosmological model featuring early dark energy (EDE) and massive neutrinos can alleviate cosmological tensions in a way which bypasses the potential problems EDE faces with galaxy clustering data, has been accepted for publication in MNRAS! We show that the answer is…“yes and no”, in the sense that our paper really reinforces the idea that prior volume effects are very important for EDE, to the extent that some of those which were previously described as problems, just maybe aren’t really problems in the first place. Kudos to Alex and Laura, two outstanding PhD students (though Laura is off to her first postdoc as a Miller fellow at JHU), who did all the heavy-lifting on this paper! It has been quite a journey, considering this paper was born out of Alex’s MSc thesis (Alex did his Part III in Cambridge with me, Blake, and George Efstathiou), whose project was conceived on a stuffy afternoon of July 2020, deep in lockdown period, while the first referee report was humongous to say the least, but really helped improve the paper! You can find the preprint version of the paper on arXiv: 2207.01501.
William Giarè wins STSM grant to visit Trento
We’ll have visitors soon: William Giarè, currently a postdoc at the University of Sheffield, has won a COST short-term scientific mission (STSM) within the CosmoVerse COST Action, which will allow him to visit the University of Trento! COST STSM grants are individual mobility and collaboration grants which are aimed towards fostering collaborations between researchers within a given COST Action. William will be visiting Trento at some point in March, and we plan on finalizing and starting up a number of projects, broadly related to the subject of cosmological tensions, ranging from the nature of dark energy, to the S8 tension “done properly” (I guess you’ll have to wait to see what we mean). We have several interesting things we want to discuss, and I look forward to the visit! Congratulations William!
LQG and Sgr A* paper accepted in ApJ!
The year is off to a truly great start research-wise: my paper with Misba Afrin and Sushant Ghosh, where we test two Loop Quantum Gravity (LQG, which is an interesting candidate framework for quantum gravity)-inspired rotating black hole space-times against the Event Horizon Telescope image of Sgr A*, the black hole at the center of our galaxy, has just been accepted for publication in ApJ! We use the size and shape of the shadow to place limits on a parameter which basically quantifies the strength of LQG effects. Our bounds are of course comparatively weak, but at the same time are interesting as a proof of principle given that there are very few ways (if any at all!) to test LQG from the observational point of view. And kudos to Misba, an outstanding PhD student at Jamia Millia Islamia, who did basically all the heavy-lifting on this paper! You can find the preprint version of the paper on arXiv: 2209.12584.
Holidays
I’m officially off for Christmas holidays as of today! Not that I’m actually going anywhere, because COVID decided to kindly pay us an unsolicited visit, so for the moment we’re locked at home ad libitum. Best wishes for the festive season to everyone, and see you in 2023!
KICC report out
The Kavli Institute for Cosmology, Cambridge (KICC) 2021 annual report is finally out: www.kicc.cam.ac.uk/files/kicc2021_report_medium.pdf
I feature in various entries, especially a research piece on direct detection of dark energy written together with Anne Davis (Pages 37-38). Enjoy the read (and thanks to KICC for having sent me a physical copy), and I guess this is me officially signing off from Cambridge!
Physics of the Dark Universe
It’s a great honor to announce that today I start a new role as Editor of Physics of the Dark Universe, one of the leading journals in cosmology and astroparticle physics. The Editor-in-Chief is Stefano Profumo, and other fellow Editors are Hong-Jian He and Ryan Foley. The journal has undergone a significant editorial reshuffle, with only Stefano left from the previous generation, whereas I basically replace Alessandra Silvestri and Luca Amendola (whom I thank for indicating me as their heir!). Interestingly, the journal has always been very “Italian”, with previous editors besides Alessandra and Luca including Licia Verde, Gianfranco Bertone, and Filippo Vernizzi, but I will actually be the first Italy-based Italian editor. Looking forward to this new adventure!
CosmoVerse
As of today I am officially a member of the CosmoVerse COST (European Cooperation in Science and Technology) Action, an European network of like-minded people with a particular interest in cosmological tensions, aiming at fostering interdisciplinary research. The Action is chaired by Jackson Levi Said at the University of Malta, whereas the Vice Chair is my friend and colleague Eleonora Di Valentino. I look forward to many interesting discussions, workshops, and seminars that will come out of CosmoVerse!
New (first) group member!
Today Davide Pedrotti joins my group as a new Master’s student. Davide is enrolled in the Trento-Tübingen Double Degree, and will be jointly supervised by me in Trento, and by Prof. Kostas Kokkotas in Tübingen. While the finer details remain to be defined, Davide’s thesis will be on the topic of quasi-normal modes of black holes beyond GR, their use in testing gravity, and potentially their connection to black hole shadows. Welcome Davide, and looking forward to our work together!
More media coverage for primordial graviton background paper
Over the past few weeks our primordial graviton background paper has been receiving a tremendous amount of media attention (in no small part due to the excellent joint Cambridge-Harvard press release and to its being picked up by Phys.org), particularly in the Italian and Spanish-speaking media. Particularly noteworthy is the coverage from Media INAF:
www.media.inaf.it/2022/11/04/vagnozzi-inflazione/
Remarkably, a few local Trentino Alto-Adige newspapers also picked up on this (first time for me appearing in a newspaper from Trentino):
www.lavocedeltrentino.it/2022/11/16/dubbi-sulla-nascita-del-cosmo-nel-team-anche-un-ricercatore-delluniversita-di-trento/ (La Voce del Trentino)
www.ildolomiti.it/ricerca-e-universita/2022/fondo-di-gravitoni-lo-studio-di-vagnozzi-unitn-e-del-collega-loeb-apre-una-nuova-porta-per-falsificare-il-paradigma-piu-accreditato-sulla-formazione-delluniverso (Il Dolomiti)
I particularly enjoyed the interview with Sara De Pascale from il Dolomiti, whose piece (in Italian of course) I highly recommend!
Regretfully, a number of other pieces were scientifically incorrect or misleading at best, suggesting that Avi and I claim that inflation is ruled out and should be replaced by a Big Bounce - let me clearly state once and for all that we said no such thing and made no judgement call on the status of inflation (in fact, in the second paragraph of the paper we explicitly write “Here we do not seek to take sides in the debate”…), so these issues simply amount to bad or click-bait journalism.
Press release for primordial graviton background paper
Following the publication of our primordial graviton background paper in ApJ Letters, both the University of Cambridge and Harvard University have issued a joint press release which beautifully summarizes our results, and which you can find at the following links:
www.cam.ac.uk/research/news/can-cosmic-inflation-be-ruled-out
www.cfa.harvard.edu/news/can-cosmic-inflation-be-ruled-out
Enjoy the read!
Primordial graviton background paper published in ApJ Letters!
My paper with Avi Loeb on the primordial graviton background, which I previously reported on in an earlier news item, has now officially been published in ApJ Letters! The full bibliographic coordinates for the paper are Astrophys. J. Lett. 939 (2022) L22. Here is the link to the paper (which is published Open Access).
ERC Starting Grant application submitted!
Right on the deadline, I submitted my ERC Starting Grant application. Obviously I chose Trento as host and, albeit much less obviously, “TRENTO” as acronym.* It was a huge amount of work and, I won’t lie, I know the chances of even just making it to the interview stage are meager to say the least. However, I have decided that I will openly report the outcome of the evaluation here in this news section, for a simple reason: in academia there is a tendency to only discuss one’s successes, whereas openly talking about one’s insuccesses is considered somewhat of a “taboo”. I hope that by openly discussing a (likely) failure/insuccess, I will help normalizing this type of discussions which, while often done in oral form, are rarely done in written form - I believe this can only make for a healthier community (I’ll note I have been prompted also by Natalie Hogg’s excellent blog, which I regularly read and highly recommend, and which does not shy away from openly discussing lack of success). So, regardless of the outcome, I will get back with an update on this in March, while in the meantime enjoying a deserved break!
*Just because it already worked once: my successful Marie Skłodowska-Curie Fellowship application, which would have been hosted by the University of Padova had I not declined it, indeed had “PADOVA” as acronym.