Gravitational Wave Probes of Fundamental Physics

Session

Overview talks

11 Nov 2019, 13:10

Riet (Volkshotel, Amsterdam, The Netherlands)

75. Dense matter equation of state constraints from NICER

Anna Watts

11/11/2019, 13:10

Overview talk

NICER, the Neutron Star Interior Composition Explorer, is an X-ray telescope that was installed on the International Space Station in 2017. Its mission is to study the nature of the densest matter in the Universe, in the cores of neutron stars. NICER does this by exploiting the effects of General and Special Relativity on radiation emitted by hotspots at the magnetic polar caps of X-ray...

80. Gravitational-wave echoes

Paolo Pani

11/11/2019, 13:40

Overview talk

Gravitational wave (GW) astronomy allows us for unprecedented tests of the nature of dark compact objects and to probe into outstanding foundational issues, such as the fate of spacetime singularities and the loss of unitarity in Hawking evaporation. In this context, I will discuss a striking signature of new physics at the horizon scale: GW “echoes” in the postmerger ringdown phase of a...

59. Cosmological Tests of Gravity with Gravitational Waves

Tessa Baker (Queen Mary University of London)

12/11/2019, 09:00

Overview talk

The first direct detections of gravitational waves have had a strong impact on attempts to extend GR in the cosmological regime. In particular, GW170817 effectively ruled out some significant chunks of the modified gravity model space. I’ll summarise what the theoretical options for extensions of GR are, and what we’ve learnt about them from gravitational waves so far. I’ll also talk briefly...

76. New prospects in numerical relativity

helvi witek (KCL)

12/11/2019, 09:30

Overview talk

Both observations and deeply theoretical considerations indicate that general relativity, our elegant standard model of gravity, requires modifications at high curvatures scales. Candidate theories of quantum gravity, in their low-energy limit, typically predict couplings to additional fields or extensions that involve higher curvature terms.

At the same time, the breakthrough discovery of...

92. Hearing the sirens of the early Universe: Primordial Black Holes and Gravitational Waves

Bradley Kavanagh (GRAPPA, University of Amsterdam)

12/11/2019, 14:00

Overview talk

Since the first detections of gravitational waves (GW) from merging binary black holes (BH), there has been a renewed interest in the possibility that at least some of these BHs could be primordial in origin. I will briefly discuss motivations for such primordial black holes (PBHs), formed from the collapse of large over-densities in the early Universe. I will then examine the on-going debate...

52. Simulating black hole dynamics and gravitational wave emission in galactic-scale simulations

Peter Johansson (University of Helsinki)

12/11/2019, 14:30

Overview talk

We will briefly review how supermassive black holes (SMBH) are modelled in galactic-scale simulations. Recently, large-scale cosmological simulations have been used to predict the gravitational wave background. These simulations typically rely on semi-analytic models to describe the small-scale black hole binary dynamics and gravitational wave emission, as these processes cannot be directly...

83. Clarifying the Hubble Constant Tension

Stephen Feeney (University College London)

13/11/2019, 09:00

Overview talk

Our best estimate of the Universe's current expansion rate (the Hubble constant) from the local Universe (via the Cepheid distance ladder) is in four-sigma tension with the value extrapolated from cosmic microwave background data assuming the standard cosmology. Whether this discrepancy represents physics beyond the Standard Model or deficiencies in our understanding of the data is the subject...

84. Phase Transitions, Dark Sectors and Gravitational Waves

Pedro Klaus Schwaller (Mainz University)

13/11/2019, 09:30

Overview talk

I will give an overview on gravitational waves from phase transitions, and then focus on specific hidden sector scenarios such as dark photons or axions, and discuss how they could be probed by future gravitational wave observations in pulsar timing arrays, space and ground based detectors.

86. Gravitational probes of exotic compact objects

Dr Djuna Croon (TRIUMF)

13/11/2019, 14:10

Overview talk

In this talk I will discuss experimental probes of dark compact objects in the new era of gravitational wave astrophysics. Such proposed objects include scalar (boson) stars, Q-balls, and dark matter clumps inside neutron stars. I will review the properties that will help us distinguish them from astrophysical objects, and the resulting gravitational wave phenomenology. I will also discuss...