Astrophysics & Particle Physics-APPC 2026

Gravitational Waves are distortions of the fabric of spacetime produced by accelerating massive bodies, e.g., colliding black holes, neutron stars, or supernovae. Foreseen by Einstein's theory of general relativity, these waves travel at the speed of light, broadcasting knowledge about their origins and about spacetime itself.Measurement of gravitational waves is dependent upon extremely sensitive observatories such as LIGO, Virgo, and KAGRA, which monitor tiny spacetime distortions through laser interferometry. The first direct detection in 2015 verified Einstein's prediction and ushered in a new era of multi-messenger astronomy, enabling simultaneous observation of electromagnetic and gravitational signals. Gravitational waves also give us special knowledge on compact object mergers, including black hole binaries and neutron star collisions. During the merger of two neutron stars, the event can emit a kilonova, heavy element nucleosynthesis, and gamma-ray bursts. They enable astronomers to experiment on extreme physics under conditions that cannot be replicated on Earth.

The investigation of gravitational waves also explores the nature of black holes, relativistic dynamics, and high-energy astrophysical processes.Waveforms contain information on the masses, spins, and orbital parameters of merging bodies, allowing for accurate modeling of extreme gravitational interactions.Gravitational wave astronomy supplements traditional electromagnetic observations, offering a new window on the universe. It enables the observation of unseen cosmic phenomena, tracing compact object populations, proving general relativity within strong-field regimes, and studying the early universe.By observing and interpreting gravitational waves, scientists acquire vital information on stellar evolution, compact object formation, cosmology, and spacetime dynamics itself. Gravitational waves are a foundation of contemporary astrophysics, linking theoretical physics to observational achievements and transforming our perception of the universe.