# 3rd Seminar on Gravitational Waves and Numerical Relativity

## Information

• Date: Sep. 12 (Fri.), 2018, 1 pm - 5 pm
• Venue: Room 501, Building #56, SNU

## Sessions

• Gravitational-Wave Fringes at LIGO: Detecting Compact Dark Matter by Gravitational Lensing
• Speaker: Sunghoon Jung (SNU)
• Abstract: Utilizing gravitational-wave (GW) lensing opens a new way to understand the small-scale structure of the universe. We show that, in spite of its coarse angular resolution and short duration of observation, LIGO can detect the GW lensing induced by small structures, in particular by compact dark matter (DM) of $$10 − 10^5 M_{\odot}$$, which remains an interesting DM candidate. The lensing is detected through GW frequency chirping, creating the natural and rapid change of lensing patterns: frequency-dependent amplification and modulation of GW waveforms. As a highest-frequency GW detector, LIGO is a unique GW lab to probe such light compact DM. With the design sensitivity of Advanced LIGO, one-year observation by three detectors can optimistically constrain the compact DM fraction as small as $$f_{\rm{DM}} \ge 10^{−2}$$.
• Gravitational Waveform Modulation from Binary Black Hole Spin Precession
• Speaker: Hee-Suk Cho (PNU)