Astrophysics and Cosmology

Thirteen full-time faculty members are joined by staff, postdocs, and students in research on astrophysics and cosmology. Major areas of research include:

• theories of the very early universe (Khoury, Trodden);
• approaches to cosmic acceleration, including modified gravity (Jain, Khoury, Sheth, Trodden);
• the properties of dark matter and dark energy, and their influence on the formation of galaxies (Bernstein, Devlin, Jain, Sako, Sanderson, Sheth);
• the nonlinear growth of structure in the Universe (Bernstein, Jain, Sheth);
• the evolution of galaxies through the epoch of reionization and into the recent era (Aguirre, Bernardi, Lidz);
• millimeter and sub-millimeter observations of galaxy clusters, and of star and galaxy formation (Aguirre, Devlin);
• observations of transient phenomena in the Universe (Sako);
• detection of planets and planet-forming systems around nearby stars (Blake, Devlin, Jain); and
• observations of the Solar System beyond Neptune (Bernstein, Blake, Sako).

We address these questions from many angles: 

• developing new instrumentation in the optical, millimeter, and sub-millimeter regimes; 
• observations from the radio through x-ray; 
• analysis of large survey datasets; 
• computation and simulation; 
• and theory. 

There is close collaboration between the astrophysics group and Penn researchers conducting laboratory and astrophysical studies of the nature of dark matter (Klein, Sanderson) and theoretical studies of gravitational and dark-sector physics (Khoury, Trodden). Many members of the department apply techniques from data science and machine learning to astronomical datasets (Bernardi, Jain, Sako, Sanderson).