# DEPARTMENT OF PHYSICS / HIP JOINT COLLOQUIA / SEMINARS

## HIP seminar room A315

**Tuesday 2 May 2017 at 17.00 in E204: Gia Dvali (Munich) Note time and place!**

*The secret quantum life of black holes*

Abstract: TBA**Thursday 4 May 2017 at 10.15 in A315: Hannu Paukkunen (Jyväskylä)**

*Nuclear PDFs today*

Abstract: I will review the present status of global determination of nuclear PDFs, Parton Distribution Functions. A special emphasis will be given to the recent Eskola-Paakkinen-Paukkunen-Salgado (EPPS16) analysis, which is the first one to include constraints from the LHC proton-lead collisions.**Tuesday 9 May 2017 at 10.15 in A315: Jim Olsen (Princeton, CERN)**

*TBA*

Abstract: TBA**Thursday 11 May 2017 at 10.15 in A315: Arttu Pönni (Helsinki)**

*TBA*

Abstract: TBA**Tuesday 16 May 2017 at 10.15 in A315: Mauri Valtonen (Turku)**

*Post-Newtonian components of a gravitational wave*

Abstract: The direct detection of a gravitational wave from GW150914 in September 2015 opens up a new window to the study of the universe. Even though the effects of gravitational waves in astronomical systems have been indirectly observed since 1974, this was the first confirmation of their existence. I will describe the history of the method leading to the detection, and the properties of the merging binary black hole system in GW150914. One of the key issues in the analysis of gravitational wave events is the theoretical treatment of the Post-Newtonian components of the wave. Until now the lowest order Newtonian component has been enough, but in the analysis of black hole mergers one has take into account higher orders. I will discuss the situation in the binary black hole system OJ287 and show that it is necessary to include tails (scattering of the waves from themselves) while the memories of past waves can be neglected. Truncating the series at the first post-Newtonian order (as is often done), leads to a serious error.**Tuesday 30 May 2017 at 10.15 in A315: Tommaso Dorigo (Padova)**

*Controversial Phenomena in Collider Data and the Five Sigma Criterion in HEP*

Abstract: Extraordinary claims require extraordinary evidence. The p < 0.000029% criterion used in HEP and astro-HEP does not appear adequate to cover all experimental situations. The seminar will start with a short history of anomalies found in HEP data and their resolution, and then focus on the statistical problem of defining a proper discovery level for new phenomena and on the non-trivial issues it entails.**Wednesday 31 May 2017 at 10.15 in A315: Marco Panero (Torino)**

*Non-equilibrium theorems from statistical mechanics and their applications in lattice QCD*

Abstract: In statistical mechanics, Jarzynski’s and Crooks’ theorems relate the free-energy difference between an initial and a final statistical ensemble (both at equilibrium), to the distribution of work done on the system, when, starting from a configuration of the initial ensemble, it is driven towards the final one, through a sequence of transformations out of equilibrium. In this talk, I will discuss how these theorems can be applied in numerical simulations of QCD and QCD-like theories on a lattice.**Thursday 1 June 2017 at 10.15 in A315: Malak Khouchen (Brno)**

*Fundamental strings and D1 branes on deformed AdS3 x S3 background*

Abstract: In this talk I describe results derived in two of my papers that were published in Phys. Review D and JHEP. In the first one we analyzed dynamics of fundamental string in deformed AdS3 x S3 space-time where we find giant magnon solutions for strings moving in this background which reproduces the celebrated Hofman-Maldacena dispersion relation in the limit when the deformation parameter goes to zero. In the second paper we analyzed D1-brane as a natural probe in the deformed AdS3 x S3 background with non-trivial Ramond-Ramond two form. We find static and time-dependent solutions of D1-brane equations of motion. We find that the behavior of these solutions crucially depends on the value of the deformation parameter and we discuss their relations to Anti-de Sitter D-branes found by K. Bachas.**Tuesday 6 June 2017 at 10.15 in A315: Daniel Fernández (Reykjavik)**

*TBA*

Abstract: TBA**Tuesday 13 June 2017 at 10.15 in A315: Kent Yagi (Princeton)**

*TBA*

Abstract: TBA

Hopefully the up to **50 min + 10 min discussion long **seminar/colloquium will be understandable to a wide audience.

Contacts: Keijo Kajantie (keijo kajantie at helsinki fi) [department / HIP seminar],

Francesco Montanari (francesco montanari at helsinki fi) [cosmo seminar]

**Other related seminars**

Friday 10-12 seminar series in D117: Astrophysics seminar.

Mathematical Physics Seminar and Workshop series Wed 14-16 in Exactum C123.