Weinberg Institute Seminar with Tejaswi Venumadhav Nerella

Abstract: General Relativity predicts that gravitational wave (GW) signals from merging binaries contain a series of overtones, or harmonics, whose frequencies are integer multiples of the orbital frequency. Modeled searches for GW signals use a family of waveforms, called a template bank, to define a search space. Nearly all previous modeled searches in the LIGO-Virgo data used templates containing only the dominant quadrupole mode to save on computational cost, and under the expectation that adding the extra complications degrades search sensitivity. We will describe a new method to include higher modes in the search pipeline that does not significantly increase the computational cost, and boosts the sensitivity across a wide region of parameter space, especially to the highest-mass binary black hole (BBH) mergers. Implementing this method yields a detection of ~10 new candidate signals in the LIGO-VIRGO O3 data. Some of the new BBH candidates have astrophysically interesting properties such as BH masses in the IMBH and pair-instability mass gap ranges, asymmetric mass ratios, positive effective spins and high-redshifts (1<z<2).