The direct detection of gravitational waves promises to open up a new spectrum that is otherwise mostly closed to electromagnetically based astronomical observations. Detecting gravitational waves from binary black holes and neutron stars, as well as estimating their parameters, requires a sufficiently accurate prediction for the expected waveform signal.
The ground-based gravitational-wave telescopes LIGO and Virgo approach the era of first detections. Gravitational-wave observations will provide a unique probe for exploring strong-field general relativity and compact-binary astrophysics. In this talk, I describe recent predictions regarding the distributions of black-hole and neutron-star binary mergers, and progress on solving the inverse problem of turning gravitational-wave observations into astrophysical information.
Gravitational radiation promises to teach us many new
things about the universe and the world around us, but all attempts to observe
gravitational waves have so far been unsuccessful. I will discuss some of the challenges we need
to overcome in our quest to detect this elusive form of energy, and how
tackling these challenges is opening new windows on fundamental physics. I will show, specifically, how novel data
analysis strategies have been used to combat detector noise in searches for
In the last few years several interesting phenomena associated to the interaction between massive black holes and fundamental bosonic fields have been discovered. I present a selection of them, including superradiance instabilities of spin-0, spin-1 and spin-2 fields, floating orbits in extreme-mass ratio inspirals and black-hole spontaneous scalarization. The theoretical potential of these effects as almost-model-independent smoking guns for exotic particles and modified gravity, as well as their limitations in realistic astrophysical scenarios, are discussed.
Observational cosmology, with particular focus on the formation and evolution of large scale structures in our universe like clusters of galaxies as large as 500 million light years. “Weighing” the universe, and mapping out the mysterious dark matter it contains.
The origin and evolution of the largest observable structures in the universe (much larger than entire galaxies); understanding why the expansion of the universe is accelerating. Observational techniques: cosmic microwave background, gravitational lensing and gravity waves.
Cosmology and cosmological implications of quantum gravity. Observable effects in cosmology help to identify the limits of general relativity, which could potentially be surpassed by modified theories of gravity and/or quantum gravity.
String theory, the high energy frontier of elementary particle physics, grand unifications into a single framework, mathematical beauty and supersymmetries, and uncovering the quantum structures of space and time.
What, exactly, happened around the time of the Big Bang? Exploring new models inspired by superstring theory and supergravity, e.g. ones in which we live on “branes” that collide with a “big bang”. Satellite experiments to test such models.
Cosmology as a natural meeting ground for fundamental theory (e.g. superstring theory or quantum gravity) and observations. Exploring how seeds laid down in the very early universe developed into the large scale structure we observe in the universe today.