Fredagskollokvium: The Dark Universe in the Era of Gravitational Wave Astronomy
Miguel Zumalacarregui, Max Planck Institute for Gravitational Physics, Germany.
Novel Gravitational Wave (GW) observations have the potential to reveal the nature of dark energy and dark matter, the mysterious substances making up 95% of the universe’s energy and driving its expansion and the formation of structures within. I will tell two stories about the virtuous circle between GWs and “traditional” cosmological observations.
The first one is on how dark energy theories motivated by tensions between different datasets were swiftly ruled out by the first multi-messenger GW detection. These scenarios modified the GW speed, which was measured exquisitely following the coincident arrival of GWs and a gamma rays from the neutron star merger detected in August 17th, 2017.
The second story is about how a dark matter theory invoked to explain LIGO data was ruled out by a “traditional” cosmological observation. In this scenario dark matter is made of primordial black holes, formed in the first instants of the universe’s history. These black holes, if abundant enough, would likely magnify small light sources via gravitational lensing. The lack of this magnification on type Ia supernovae (originally used used to discover dark energy) ruled out stellar mass primordial black holes as the sole dark matter component.
These examples highlight the virtuous circle between different observations and the potential of GW astronomy to shape new directions in cosmology and fundamental physics.
Please join via Zoom at https://uio.zoom.us/j/67198034488?pwd=ekhUb1p5UTEzZGdueG9CQ2pISVErZz09
Meeting ID: 671 9803 4488
Attendees will be muted during the colloquium, but will have the opportunity to ask questions at the end by clicking on the "raise hand” button