Jonathan I. Katz

Jonathan I. Katz

​Professor of Physics
PhD, Cornell University
research interests:
  • Astrophysics
  • Soft Matter
  • Climate
  • Applied Physics

contact info:

mailing address:

  • Washington University
    CB 1105
    One Brookings Drive
    St. Louis, MO 63130-4899

Professor Katz's current work focuses on the recently discovered astronomical Fast Radio Bursts. These brief (millisecond) bright events are believed to originate at "cosmological" distances, but their sources and mechanisms remain a mystery. He has also proposed a novel explanation of Boyajian's Star, in which its dips are the result of obscuration by dust rings in the outer Solar System.

The brightness of Fast Radio Bursts indicates a coherent emission process, like that of pulsars, and their brevity requires an origin in objects of neutron-star dimensions. However, they are too luminous to be pulsar pulses unless the pulsars are extraordinarily fast, strongly magnetized and efficient or are narrowly beamed. The novel hypothesis of beaming permits many other models, and the problem is to decide which is correct.

Undergraduate students working with Katz on weather data have set upper bounds on any increase in drought and storms as the climate warms and have developed novel descriptions of the changing frequency of temperature extremes. Other undergraduates have studied the properties of starch suspensions and found remarkable hysteresis in their shear stiffening behavior.

recent courses

Classical Mechanics (Physics 507)

The culminating achievements in this classical discipline are presented: Lagrangian and Hamiltonian formulation of the classical equations of motion with application to constrained systems, including action principles, the Hamilton-Jacobi equation, and Euler angles and rigid body rotation.

    Classical Electrodynamics II (Physics 506)

    Time-varying electric and magnetic fields. Electromagnetic waves and radiation; simple antennas. Waveguides and effects of dispersion. Retardation effects and special relativity.

      Energy and Environmental Physics (Physics 344)

      This intermediate-level course applies basic physics principles to this increasingly important area. It is designed for all science and engineering majors with an interest in energy and environmental issues. Topics to be covered include population trends, fossil fuel use, renewable energy sources, energy storage strategies and climate change. Particular emphasis will be given to the use of the fundamental laws of physics, such as energy conservation, as well as more general concepts such as local and global stability, chaotic behavior, probability and risk. The aim of the course is the development of analytical skills and familiarity with important concepts, in order to enable an independent and informed view of environmental problems and possible solutions. A one-year introductory physics class on the level of Physics 191-192 is required. This course may also be taken as Physics 444, which requires an additional independent project.

        Classical Electrodynamics I (Physics 505)

        Classical electromagnetism in microscopic and macroscopic forms: electromagnetic fields of and forces between charged particles. Applications to electrostatic, magnetostatic, electrodynamic, and radiation problems.