Jonathan I. Katz

Professor Katz works in a number of areas, including astrophysics, soft matter (rheology of suspensions), climate and applied physics. His current work focuses on the recently discovered astronomical Fast Radio Bursts. These brief (millisecond) bright events are believed to originate at "cosmological" distances (redshifts mostly 0.5--1) but their origin is a mystery. Their brightness indicates a coherent emission process, like that of pulsars, and their brevity requires an origin in objects of neutron-star dimensions, but they are too luminous tobe pulsar pulses. The only other astronomical event with such a rapid time scale is the rising phase of giant flares from Soft Gamma Repeaters, and Prof. Katz is investigating their possible relation and models.

Work with undergraduate students on weather data has set upper bounds on any increase in drought and storms as the climate warms. Other students have studied the properties of corn starch suspensions and found remarkable stick-slip shear stiffening behavior.

Some significant publications:

• The 35 Day Period of Her X-1, J. I. Katz, Nature Physical Sciences 246, 87 (1973) [First publication of precessing accretion discs].
• Two Kinds of Stellar Collapse, J. I. Katz, Nature 253, 698 (1975) [First recognition of superabundance and significance of X-ray sources in globular clusters].
• Physical Processes in Gamma-Ray Bursts, J. I. Katz, Astrophys. J. 260, 371 (1982) [First publication of the "magnetar model" of Soft Gamma Repeaters].
• A Model of Propagating Brittle Failure in Heterogeneous Media, J. I. Katz Journal of Geophysical Research 91, 10412 (1986) [First publication of the model later described by Bak, Tang and Wiesenfeld 1987 as "Self-Organized Criticality"].
• Low Frequency Spectra of Gamma-Ray Bursts, J. I. Katz Astrophys. J. Lett. 432 L107 (1994) [First prediction of astronomical GRB afterglows discovered in 1997].

Jonathan I. Katz's Complete Publications List