# DEPARTMENT OF PHYSICS / HIP JOINT COLLOQUIA / SEMINARS

## HIP seminar room A315

**Tuesday 20 November 2018 at 10.15 in A315: Jonathan Braden (University College London)**

*A New Real-Time Picture of Vacuum Decay*

Abstract: Quantum decay of false vacuum states via the nucleation of bubbles may have played an important role in the early history of our Universe. For example, in multiverse models that utilize false vacuum eternal inflation, the Big Bang of our observable Universe corresponds to one of these bubble nucleation events. Further, our observable Universe may have undergone a series of symmetry-breaking first-order phase transitions as it cooled, which may have produced a remnant background of gravitational waves.**Thursday 22 November 2018 at 14.00 in Exactum B123: Ville Keränen (OP Financial Services)**

*What does a theoretical physicist do in a bank?*

Abstract: At first sight banking doesn’t seem like it would have much to do with theoretical physics. In this talk I will describe an example problem one faces in a bank (modelling stock prices to price derivatives) and will try to explain how it connects to theoretical physics, such as quantum field theory in curved spacetime.**Tuesday 27 November 2018 at 10.15 in A315: José Manuel Penín Ascariz (Santiago de Compostela)**

*Anisotropic D3-D5 black holes with unquenched flavors*

Abstract: We construct a black hole geometry generated by the intersection of Ncc color D3- branes and Nff flavor D5-branes along a 2+1 dimensional subspace. Working in the Veneziano limit in which Nff is large and distributing homogeneously the D5-branes in the internal space, we calculate the solution of the equations of motion of supergravity plus sources which includes the backreaction of the flavor branes. The solution is analytic and dual to a 2+1 dimensional defect in a 3+1 dimensional gauge theory, with Nff massless hypermultiplets living in the defect. The smeared background we obtain can be regarded as the holographic realization of a multilayered system. We study the thermodynamics of the resulting spatially anisotropic geometry.**Thursday 7 February 2019 at 10.15 in A315: Lars Bergström (Stockholm)**

*Primordial Black Holes as Dark Matter?*

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 A315: Astrophysics seminar.

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