Mapping the expansion history of the universe using standard candles and standard clocks

Mittwoch, 22. Mai 2019, 14:00 - 15:30
Veranstaltungsort* Library
 
Mapping the expansion history of the universe using standard candles and
standard clocks

The recent measurements of the local distance ladder H0 are in > 4 sigma tension
with the value inferred from the CMB assuming standard cosmology. This indicates the
possibility of exotic cosmological physics beyond the standard model. In this talk,
I will summarise our previous work on studying the role of systematic effects from
the Type Ia supernova (SNe Ia) wrung of the distance ladder, using them as
near-infrared standard candles as well as our study on understanding the possible
non-standard cosmologies that can resolve the Hubble tension.
We find that the inferred value of H0 from NIR SNe Ia data is consistent with the
optical value, suggesting that SNe Ia systematics are sub-dominant in explaining the
tension. Moreover, I will summarise our recent work on comparing different
non-standard dark energy models using SNe Ia in combination with BAO and CMB
distances. In addition to the local distance ladder, independent probes, e.g.
time-delay distances to lensed transients ('?'€'?'standard clocks'?'€'?') have been proposed
and used as methods for precision estimation of H0. Here, I will summarise the
ongoing work on measuring the time-delays for the first resolved, multiply imaged
SNe Ia, iPTF16geu. 


: Dr. Suhail Dhawan, Stockholm