Marios Kalomenopoulos, Sadegh Khochfar, Jonathan Gair, Arai Shun
Career Stage
Student (postgraduate)
Poster Abstract
In our project, we investigate gravitational waves (GWs) that have an electromagnetic (E/M) counterpart as probes for the inhomogeneities in the universe, and the possible degeneracy of the latter with modified gravity theories. In this poster, we show possible constraints on inhomogeneous parameters exploiting future GWs measurements and their E/M counterparts. Finally, the level of the degeneracy between modified gravity parameters and inhomogeneities are investigated, and the requirements for breaking them are quantified.
Plain text summary
The recent detection of gravitational waves (GWs), opened a new window to the Universe.
In our project, we study the impact of large-scale structures in the Universe on the propagation of GWs and their signals. We use both analytic methods and state-of-the-art cosmological simulations. The path taken through the Universe by a GW, from its source to an observer, depends on the distribution of matter as well as on the underlying theory of gravity. For example, under-dense regions can lead to “weaker” GW signals. At the same time, modified gravity theories that extend general relativity, predict among other effects, different amplitudes and propagation speeds for GWs.
The plethora of various phenomena affecting the waves can lead to multiple conclusions when analysing the data. To break such degeneracies and to devise future observing strategies we use realistic state-of-the-art cosmological simulations of structure formation that allow us to gauge the relative importance of various physical effects.
More specifically, in this work, we study how well future GW detectors can study the clumpiness of our universe. In parallel, we show that the presence of under-dense regions can lead to similar effects to those predicted by modified gravity theories. Finally, we quantify the number of future observations needed to be able to disentangle the two.
In our project, we study the impact of large-scale structures in the Universe on the propagation of GWs and their signals. We use both analytic methods and state-of-the-art cosmological simulations. The path taken through the Universe by a GW, from its source to an observer, depends on the distribution of matter as well as on the underlying theory of gravity. For example, under-dense regions can lead to “weaker” GW signals. At the same time, modified gravity theories that extend general relativity, predict among other effects, different amplitudes and propagation speeds for GWs.
The plethora of various phenomena affecting the waves can lead to multiple conclusions when analysing the data. To break such degeneracies and to devise future observing strategies we use realistic state-of-the-art cosmological simulations of structure formation that allow us to gauge the relative importance of various physical effects.
More specifically, in this work, we study how well future GW detectors can study the clumpiness of our universe. In parallel, we show that the presence of under-dense regions can lead to similar effects to those predicted by modified gravity theories. Finally, we quantify the number of future observations needed to be able to disentangle the two.
Poster file
Poster Title
Studying inhomogeneous universes and modified gravity with Standard Sirens