DEPARTMENT OF PHYSICS / HIP JOINT COLLOQUIA / SEMINARS 2024

  • Thursday 4 April 2024 at 10:15 in A315 and using Zoom: Karapet Mkrtchyan (London)
    Democratic approach to p-forms and electric-magnetic duality
    Abstract:
    I will summarize recent progress on the democratic covariant Lagrangian formulation of (chiral) p-form dynamics, including arbitrary abelian interactions. Applications include democratic formulations for the gauge sector of maximal supergravities in 10d/11d, with on-shell values of their actions consistent with AdS/CFT predictions.
  • Tuesday 9 April 2024 at 10:15 in A315 and using Zoom: David Benisty (FIAS, Frankfurt and KICC, Cambridge)
    Constraining Dark Energy from the Local Group dynamics
    Abstract:
    In this talk I’ll show a method to constrain the Cosmological Constant \Lambda from binary galaxies, focusing on the Milky Way and Andromeda galaxies. We provide an analytical solution to the two-body problem with \Lambda and show that the ratio between the Keplerian period and T_\Lambda = 2\pi/(c \sqrt{\Lambda}) \approx 63.2 Gyr controls the importance of effects from the Cosmological Constant. The Andromeda-Milky Way orbit has a period of \sim 20 Gyrs and so Dark Energy has to be taken into account.  Using the current best mass estimates of the Milky Way and Andromeda galaxies, we find the Cosmological Constant value based only on the Local Group dynamics to be lower than 5.44 times the value obtained by Planck. With future astrometric measurements, the bound on the Cosmological Constant can be reduced to \left(1.67 \pm 0.79\right) \Lambda_{\rm PL}. Our results offer the prospects of constraints on \Lambda over very different scales than previously. The Local Group provides also a completely novel platform to test alternative theories of gravity. We illustrate this by deriving bounds on scalar-tensor theories of gravity over Megaparsec scales.
  • Thursday 11 April 2024 at 10:15 in A315 and using Zoom: Christian Ecker (Frankfurt)
    TBA
    Abstract:
    TBA
  • Tuesday 14 May 2024 at 10:15 in A315 and using Zoom: Tyler Gorda (Frankfurt)
    TBA
    Abstract:
    TBA
  • Thursday 23 May 2024 at 10:15 in E204 and using Zoom: Hannu Kurki-Suonio (Helsinki)
    Farewell lecture; Hannu retires on 1 July 2024
    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) [ HIP seminar],
Jaakko Annala (jaakko annala at helsinki fi) [cosmo seminar]

New Nordic series of seminars over the web, link: https://sites.google.com/view/nordictheory/home
For more information, and to subscribe to email announcements, contact Oscar Henriksson (oscar henriksson at helsinki fi)

Other related seminars

Friday 10-12 seminar series in D114:Astrophysics seminar
Mathematical Physics Seminar and Workshop series Wed 14-16 in Exactum C123.
InstituteQ Events and Seminars