News and Updates

With our latest preprint [arXiv:2412.06887] (led by Marina De Amicis), SXS simulations have for the first time resolved fully nonlinear “tails” from merging black holes. What’s this all about?

We’re so happy that Mark Scheel, one of the senior members of the SXS collaboration, has been elected a 2024 Fellow of the American Physical Society!

We now have the first complete binary black hole inspiral, merger, & ringdown using our next-generation code SpECTRE! Our preprint [arXiv:2410.00265] presenting this first complete BBH simulation was led by Kyle Nelli (grad student at Caltech) and Geoffrey Lovelace (professor at CSU Fullerton).

What are hybrid gravitational waveforms? In meme form:

On 14 September 2015 at 4:50:45 AM Eastern standard time, LIGO detected its first gravitational waves. The waves descended on Earth from the southern hemisphere, passed through the Earth, and emerged at the Earth’s surface first at the LIGO interferometer in Livingston, Louisiana, and then, 7 milliseconds later, at the LIGO interferometer in Hanford, Washington (shown below).

To detect and characterize gravitational waves from neutron star binaries, LIGO needs good models of all possible signals. Numerical relativity can’t practically be used for every case, but it is needed to test and calibrate the simpler models that LIGO can use. Inspiral waveforms from binaries with neutron stars differ from binary black hole waveforms by the presence of tidal forces. In a recent paper, Tanja Hinderer and collaborators use SXS black hole-neutron star simulations to validate a new model of these tidal forces. They find that tidal effects can be stronger than previously expected when they come close to resonance with a neutron star’s preferred ways of ringing (its normal modes of oscillation).