# Ira Wasserman

## Kenneth A. Wallace Professor of Astronomy, Professor of Physics

### Overview

Ira Wasserman is Professor of Astronomy and Physics at Cornell University.He received his B.S. degree from MIT in 1974 and his Ph. D. from Harvard in 1978, both in physics. After three years as a postdoctoral research associate and fellow, he joined the Cornell faculty in 1981. Professor Wasserman does research on relativistic astrophysics. Recent areas of interest are properties of Type II superconducting cores of neutron stars, nonlinear development of the r-mode instability of neutron stars and implications for their maximum spin rate, cosmological observations in the inhomogeneous universe, and the birthplaces of cosmic rays.

### Research Focus

My research covers a range of topics in theoretical astrophysics, ranging from cosmology particularly the nature of dark energy and the cosmological constant, and the possibility for detecting observational signatures of superstring inflation and neutron star astrophysics particularly long term variations in pulsar rotation.

### Publications

- ''Toroidal magnetic fields in type II superconducting neutron stars,''T. Akgun and I. Wasserman, MNRAS, 383, 1551 (2008)
- "Cosmic Strings as the Source of Small-Scale Microwave Background Anisotropy'', L. Pogosian, S.-H. H. Tye, I. Wasserman and M. Wyman, JCAP, 02, 013 (2009)
- "Spinning down newborn neutron stars: Nonlinear development of the r-mode instability'', R. Bondarescu, S. A. Teukolsky and I. Wasserman, Phys. Rev. D, 79, 104003 (2009)
- "Lemaitre-Tolman-Bondi cosmological models, smoothness, and positivity of the central deceleration parameter'', R. A. Vanderveld, E. E. Flanagan and I. Wasserman, arXiv:0904.4319 (2009)
- "Modification to the luminosity distance redshift relation in modified gravity theories'', E. E. Flanagan, E. Rosenthal and I. Wasserman, Phys. Rev. D, 79, 044032 (2009)
- "Luminosity distance in Swiss cheese cosmology with randomized voids. II. Magnifcation probability distributions", with E. E. Flanagan, N. Kumar, and R. A. Vanderveld, Physical Review D, 85, 023510 (2012).
- "Guilt by Association: Finding Cosmic Ray Sources Using Hierarchical Bayesian Clustering", with K. Soiaporn, T. Loredo, D. Cherno and D. Ruppert, (2012) [arXiv:1206.3540]
- "Luminosity distance in Swiss cheese" cosmology with randomized voids. III. e ects of small scale structure", with E. E. Flanagan and N. Kumar, submitted to Physical Review D, 2012 [arXiv:1207.3711]
- "Hierarchical Bayesian Framework for Modeling the Production, Propagation and Detection of Ultra High Energy Cosmic Rays", with K. Soiaporn, T. Loredo, D. Chernoff and D. Ruppert, submitted to the Annals of Applied Statistics, 2012 [arXiv:1206.4569]