Searching for New Physics in the Lab and the Sky

This award funds the research activities of Professor Ken Van Tilburg at New York University.

The current set of physical laws --- as encapsulated within the Standard Models of Particle Physics and Cosmology --- provide an exquisitely accurate and precise description of all known phenomena in nature. However, several puzzles still remain. The most tangible shortcoming is that the microscopic nature of dark matter, a mostly inert component comprising most of the matter density of the Galaxy and the Universe, is unknown, despite the troves of evidence for its existence through its gravitational influence. In his research, Professor Van Tilburg aims to develop observational probes of dark-matter structures smaller than ever detected before, using methods based on the gravitational deflection of starlight caused by small and otherwise invisible clumps of dark matter. Using X-ray satellites and terrestrial dark matter experiments, he will also aim to detect weakly-interacting low-mass particles, a motivated class of dark-matter candidates which are produced in the cores of stars. Research in this area advances the national interest by seeking to answer one of the most fundamental questions in physics, namely that of understanding what particle(s) comprise the dark matter. Professor Van Tilburg will also involve graduate students and a postdoc in his research, thereby training the next generation of junior scientists in this burgeoning new field at the intersection of particle physics and astrophysics. He will also visit local high schools to give public lectures about particle physics and cosmology and to educate students from underrepresented groups about pursuing scientific career paths.

In a first research avenue, Professor Van Tilburg and his group will conduct a suite of analyses of time-domain, astrometric, weak gravitational lensing on public astronomical data sets, to search for entirely non-luminous dark matter structures lighter than 100 million solar masses. In particular, he aims to develop a data analysis pipeline to search for transient astrometric deflections in Gaia time-series data from ultra-compact dark-matter structures as well as from astrophysical compact remnants and black holes. He also seeks to analyze the correlated shifts in celestial proper motions and accelerations of background sources induced via gravitational lensing by more extended dark-matter structures. A (non-)detection of such small-scale structures would provide crucial new constraints on the microphysics of dark matter, as well as the primordial seeds of structure formation on small scales. In a second research avenue, Professor Van Tilburg will study a recently introduced phenomenon, dubbed "stellar basins", wherein weakly-coupled particles can be emitted from the entire stellar volume onto bound orbits whose density accumulates over time. This effect is generic for any particle type and important if the particle has a rest-mass energy not too far removed from the temperature in the stellar interior. Van Tilburg conjectures that phenomena associated with stellar basins --- direct detection in the laboratory and indirect detection in telescope observations --- will form the leading probes of any particle in the mass range from a few eV to hundreds of keV. The objective of this research avenue is to work out this phenomenology in detail: calculating all production mechanisms, performing computations for the observable signals, analyzing publicly available data, and interpreting the results in terms of the parameter space of the models.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

Award Number: 2622106
Principal Investigator: Ken Van Tilburg
Funds Obligated: $70,650
State: CA