Visit to CERN

I am just back from CERN, where I stayed over this week to visit Diego Blas at the CERN THeory Division and to give the talk "Compact Objects as Dark-Matter Probes".

Some sparse thoughts on the visit:

1) On the first night, I checked in at a hotel in Geneva instead of staying at the CERN hostel. That was a very bad move. Everything in Geneva is unbelievable expensive and the hotel (albeit 3 star and averaged rated) turned out to be quite bad. I got bed bugs, i am still full of pinches, and i'm still trying to disinfect my clothes at home...

2) On the other hand, the hostel at CERN (where I stayed for the rest of the week) was excellent. The room was clean and cozy and equipped with a large desk. Everything at CERN seems to be designed to simply researchers' life and work.

3) I was impressed by the low average age of people working at CERN. About 10K work at the center and most of them are young PhDs or postdocs. The comparison with the average Italian university, where most of the faculty members and staff are over 40, is impressive. I recently read an interview by CERN Director Fabiola Gianotti, who was precisely commenting on this fact. However, experiencing it directly is a different kettle of fish.

4) Although CERN is big and experiments are scattered around a 27-km underground ring, I enjoyed the fact that most offices are located in a handful of buildings which are connected among each other. This basically means that theorists can chat over a coffee with experimentalists, or that it is easy to attend the (enormous) number of talks and lectures that are organized on a daily basis. The canteen is also common for all buildings and researchers from different collaborations and experiments meet there to have lunch (and sometimes dinner) together.

5) Overall, the atmosphere is definitely suggestive, even for someone like me who's used to see so many physicists in the same place (I guess that for the numerous students who regularly visit CERN during a school trip it must be really a unique experience).

6) I had the opportunity to meet various friends with whom I went to college in Cagliari (some of them are also authors of this blog). Funny enough, the excess of physicists from Cagliari University, especially in the LHCb experiment, is beyond 5 sigma. Thus, I had the opportunity to visit the LHCb experiment and control room, as this picture testifies:

Visit to the LHCb experiment. 
From the left to the right: Andrea (aka Scrilly), Francesco (both CERN Fellows) and me.

7) BTW, I also had the opportunity to hear more rumors around the 750 GeV diphoton resonance. Every theorist I talked to was extremely excited and sometimes confident about the possibility that ATLAS and CMS experiments have detected something new. Funny enough, every experimentalist I talked to was instead extremely cautious and, most of the time, pessimistic. I should definitely write about this in a next post but, as you probably have heard, this coming week the spotlight will all be on LIGO's announcement of the first direct detection of gravitational waves (!) No doubts on the topic of my next post (after Thursday).

Vitor Cardoso's and Thomas Sotiriou's visits @Sapienza

In the last two months we had two guests at our Department:

• Vitor Cardoso, leader of the strong gravity group at IST, was a Visiting Professor at Sapienza in December and January; some weeks ago he gave a talk on "Black holes as laboratories of fundamental physics"
• Thomas Sotiriou, leader of the gravity group "Challenging General Relativity" at Nottingham University, visited our group during the last week of January and gave a talk on "Lorentz violations, causality, and black holes".

Group picture taken [1] after a goodbye social dinner in the historical center of Rome. 
From the left to the right: Leonardo, Thomas, Vitor, Paolo, Ana and Leonardo Macelloni (an old friend from the University of Mississippi who I met at the time of my first moka machine)

[1] By chance, this picture was taken by the bodyguard of President of the Senate Renato Schifani, who was passing by while we were looking for a random photographer.

Jan Steinhoff @ Sapienza

Last week Jan Steinhoff from the Albert Einstein Institute visited our group in Rome, giving a seminar on "Effective action for compact objects and universal relations". Over the weekend, we went for some city sightseeing. Here, from left to right, Jan, Paolo and special guest Matteo are visiting the magnificient Caracalla's baths.

Visit to AEI

This week I was visiting the Max Planck Institute for Gravitational Physics (aka Albert Einstein Institute, AEI) in Golm, in the outskirts of Potsdam, in the outskirts of Berlin (this more or less reflects the number of connections that commuters living in Berlin have to take everyday). The location of the institute is really its only weakness because otherwise the place looks great.

Jan and I taking a selfie with Albert. The statue is located at the middle of a beautiful large indoor yard 
at the Albert Einstein Institute in Potsdam (Germany)

I was there to collaborate with Jan Steinhoff (see pic above) who was postdoc in Lisbon in the last few years and recently moved to the AEI to work in gravitational-wave group lead by the new Director of the institute, Prof. Alessandra Buonanno, a world-leading expert in gravitational-wave phenomenology (and also one of the key speakers of this upcoming workshop). While there, I gave a seminar on "Black holes as stong-gravity labs", presenting some recent results related to black-hole superradiance (a topic that I will cover in this blog soon). I've also took the opportunity to discuss with a lot of interesting people working at the AEI (and to have some German beers with Jan and Jordi Casanellas, who also moved to AEI from Lisbon).

Visit to the Maryland Center for Fundamental Physics

This week I was invited at the Center for Fundamental Physics in Maryland, where I gave a talk about black holes and fundamental light fields beyond the Standard Model. On the way back to the airport in Washington DC, I stopped by the Air & Space museum. Here is a picture of me before the Hubble Space Telescope.
BTW, in The Mall in DC all museums belong to the Smithsonian Institute and they are free, amazing!)