Massive astrophysical compact halo objects (MACHOs) are viable compact dark matter (DM) candidates, the presence of which in the interstellar medium will lead to lensing of electromagnetic (EM)/gravitational-wave (GW) signals. Various EM lensing searches have constrained the DM density fraction, f_DM, in the form of MACHOs better than f_DM < 10^(−5) in the mass range < 10^(-16) M_sun and > 10^5 M_sun. On the other hand, LIGO-Virgo detectors (10Hz < f < 100Hz) are well suited to probe MACHOs in the mass range 10 − 10^5 M_sun via GW lensing. The lensed lens waveform will have a frequency dependent magnification/demagnification in the wave-optics limit (λ_(GW) ∼ R_(Sch)^(lens) ), which is true for MACHOs. In this talk, we will discuss how the search of lensing signature in GW events observed by LIGO-Virgo can be used to put better constraints on f_DM
Seminar
Speaker
Apratim Ganguly (ICTS-TIFR, Bangalore)
Date & Time
Fri, 31 January 2020, 11:30 to 12:30
Venue
Emmy Noether Seminar Room, ICTS Campus, Bangalore
Resources
Abstract