Professor Riles carries out research into the fundamental forces of nature, working in both gravitational wave and elementary particle physics.
Professor Riles is a member of the LIGO Scientific Collaboration (LSC), which in September 2015 discovered gravitational waves from the merger of two massive black holes. This $300 million project, led by Caltech and MIT, operates 4-km Michelson laser interferometers at sites in Hanford, Washington and Livingston, Louisiana. These interferometers are designed to measure minute disturbances in space itself to a relative precision better than 1 part in a billion trillion (10-21). Transient "ripples in space" can emanate from violent but distant astrophysical phenomena, including colliding black holes or neutron stars and from supernovae. Using LIGO data, the Michigan gravitational wave group has placed upper limits on longer-lived but still weaker (<10-24) ripples from unknown, rapidly spinning neutron stars in the Milky Way. Searches are now under way for gravitational waves emitted by isolated neutron stars using an algorithm called PowerFlux and for binary neutron stars, using an algorithm called TwoSpect. Both programs were developed by the University of Michigan group. In addition, the group has carried out extensive work on LIGO detector characterization, including calibration, and on detector commissioning.
Professor Riles has also spent part of his research time in recent years studying the physics potential and the detector requirements of a future linear electron positron collider with a center of mass energy of 350 GeV and higher.
Observation of Gravitational Waves from a Binary Black Hole Merger, Phys. Rev. Lett. 116, 061102 (2016).
First all-sky search for continuous gravitational waves from unknown sources in binary systems, Phys Rev. D 90, 06201 (2014).
Gravitational Waves: Sources, Detectors and Searches (K. Riles), Prog. Part. Nucl. Phys. 68, 1 (2013).
All-Sky Search for Periodic Gravitational Waves in the Full S5 LIGO Data (J. Abadie et al), Phys. Rev. D 85, 022001 (2012).
An All-Sky Search Algorithm for Continuous Gravitational Waves from Spinning Neutron Stars in Binary Systems (E. Goetz and K. Riles), Class. Quant. Grav. 28, 215006 (2011).
All-Sky LIGO Search for Periodic Gravitational Waves in the Early S5 Data, (B. Abbott et al), Phys. Rev. Lett 102, 111102 (2009).