Tuesday November 12, 2pm, room 110
Miguel Zumalacarregui (UC Berkeley & IPhT Saclay) : Testing Gravity and Dark Energy with Cosmology and Gravitational Waves
Alternative theories of gravity may provide viable models of cosmic acceleration with the possibility of alleviating shortcomings of the standard paradigm such as discrepant measurement of the Hubble parameter. I will present recent progress in constructing viable, yet extremely predictive theories of gravity and dark energy, extracting their cosmological implications and testing them with data, current and forthcoming. I will also present how most of these theories affect the propagation of gravitational waves. In particular, the speed of gravitational waves provides the most stringent test for a large class of theories, which have been recently ruled out by the GW speed measurement following the neutron star merger GW170817. Other effects on gravitational wave propagation (damping, modified dispersion and oscillations) can be used to test the landscape of gravitational theories.
Tuesday October 8, 11am, room 110
Federico Urban (Inst. of Physics Prague) : Binary pulsars as probes for ULDM
Binary pulsars can very precise detectors for Ultralight Dark Matter : I will show how we can recover several properties of Ultralight Dark Matter (spin, mass, interactions) by looking at secular variations of the binary orbital parameters.