2nd Nordic Cosmology Meeting

Session

Invited talk

12 Mar 2025, 11:30

E204 (University of Helsinki)

38. Nonlinear Cosmological probes of gravity theories beyond General Relativity

David F. Mota

12/03/2025, 11:30

Invited talk

Several modifications to general relativity have been proposed to explain the nature of dark energy and the accelerated expansion of the Universe. In this talk, I will review the present status of modified theories of gravity in the light of astrophysical probes of gravity in the weak-field regime, ranging from stars to cosmological scales. I begin by setting the scene for how theories beyond...

44. Direct detection of dark matter: overview

Matti Heikinheimo (University of Helsinki and Helsinki Institute of Physics)

12/03/2025, 12:15

Invited talk

Direct detection of scattering events of dark matter off ordinary atoms is a critical goal that would allow us to extract information about the nature of the dark matter particle. I will give an overview of the theory underlying the direct detection experiments and on the current status of these experiments. I will discuss some future prospects, focusing on the developments towards direct...

39. Quantum Tachyonic Preheating Revisited.

Anders Tranberg (University of Stavanger)

12/03/2025, 14:00

Invited talk

Tachyonic preheating is one of a few compelling mechanisms for transitioning from an inflationary, empty Universe to a hot radiation dominated Universe. The 2PI formalism allows for a correct quantum treatment of particle production and thermalisation, and is well suited for numerical implementation on the lattice. I will present an investigation of tachyonic preheating, aimed at updating...

40. The bubble wall velocity in cosmological phase transitions

Jorinde van de Vis (CERN)

13/03/2025, 10:00

Invited talk

Cosmological first order phase transitions are a promising source of gravitational waves, and a possible explanation of the baryon asymmetry and dark matter abundance. Predicting the phenomenological consequences of such phase transitions requires knowledge of the expansion velocity of the bubbles formed in a phase transition. In this talk, I will present WallGo, a software package for the...

41. LISA and its synergy with particle physics colliders

Germano Nardini (University of Stavanger)

13/03/2025, 10:45

Invited talk

One of the primary objectives of the LISA mission is to measure and characterize the stochastic gravitational-wave background (SGWB). Achieving this goal will allow LISA to explore various domains, including astrophysics, cosmology, and particle physics. This talk focuses on the latter, specifically on physics beyond the Standard Model that involves strong first-order phase transitions. We...

42. Fishing for light dark matter with pulsars (via Zoom)

Nataliya Porayko (SAI)

13/03/2025, 14:00

Invited talk

Pulsars, which are very rapidly spinning neutron stars, can be instrumental in solving the puzzle, which has perplexed the minds of the scientific community for almost a century – dark matter (DM). In the talk I will mainly focus on the light DM candidates that can be searched for in pulsar observables. The ultralight scalar field DM (also known as "fuzzy" DM), consisting of bosons with...

46. Primordial black holes and their gravitational wave signatures

Hardi Veermäe (National Institute of Chemical Physics and Biophysics (EE))

14/03/2025, 09:45

Invited talk

Primordial black holes (PBHs) are a compelling dark matter candidate that can be effectively probed through their gravitational wave (GW) signatures. In this talk, I will focus on standard scenarios in which PBHs form via the collapse of sizeable primordial curvature fluctuations. I will discuss what current pulsar timing array (PTA) measurements can tell us about stellar-mass PBHs and whether...