This is the golden age of cosmology. Once a data-starved science, cosmology has burgeoned as ground and space-based astronomical observations supply a wealth of unprecedently precise cosmological measurements. Questions that were recently the stuff of speculation can now be analyzed in the context of rigorous, predictive theoretical frameworks whose viability is determined by observational data. Finally, cosmological theory is being confronted by cosmological fact. The most surprising and exciting feature of cosmology's entrance into the realm of data-driven science is its deep reliance on theoretical developments in elementary particle physics. At the energy scales characteristic of the universe's earliest moments, one can no longer approximate matter and energy using an ideal gas formulation; instead, one must use quantum field theory, and at the highest of energies, one must invoke a theory of quantum gravity, such as string theory. Cosmology is thus the pre-eminent arena in which our theories of the ultra-small will flex their muscles as we trace their role in the evolution of the universe.

In September of 2000, the Institute for Strings, Cosmology, and Astroparticle Physics (ISCAP) was formed at Columbia University under the joint directorship of Brian Greene (Department of Physics) and Arlin Crotts (Department of Astronomy). The goal of ISCAP is to bring together theoretical physicists, astrophysicists, and observational astronomers to address key problems in particle physics and cosmology that require a broad confluence of expertise and perspective.

Although there are a number of particle astrophysics groups around the country, ISCAP has two unique features. Firstly, ISCAP is the only group with a primary focus on the ultra-high energy scales between the grand unified/inflation scale (10¹⁵ GeV) and the Planck scale (10¹⁹ GeV), where the microscopic dynamics of spacetime itself come into play. Now is the time to probe this exotic realm, which holds the answers to some of the greatest scientific mysteries, and ISCAP proposes to undertake to develop methods -- both theoretical and observational -- to do so. Secondly, ISCAP is one of the few cosmology groups with the necessary breadth of interest and experience to pursue these enquiries, having expertise in traditional particle physics, string theory/quantum gravity, particle-astrophysics, inflationary cosmology, in numerical methods and observational cosmology.

Select recent Articles by ISCAP members

• String windings in the early universe
  R. Easther, B. R. Greene, M. G. Jackson, D. Kabat.
  PDF-copy from the e-print ArXiv:hep-th/0409121.
• Detecting dark energy in orbit: The cosmological chameleon
  P. Brax, C. van de Bruck, A. C. Davis, J. Khoury and A. Weltman.
  PDF-copy from the e-print ArXiv:astro-ph/0408415.
• The foundations of observing dark energy dynamics with the Wilkinson Microwave Anisotropy Probe
  P. S. Corasaniti, M. Kunz, D. Parkinson, E. J. Copeland and B. A. Bassett.
  PDF-copy from the e-print ArXiv:astro-ph/0406608.
• Decoupling in an expanding universe: Boundary RG-flow affects initial conditions for inflation
  K. Schalm, G. Shiu and J. P. van der Schaar,
  PDF-copy from the e-print ArXiv:hep-th/0401164.
• Towards Constraints on Dark Energy from Absorption Spectra of Close Quasar Pairs
  A. Lidz, L. Hui, A. P. S. Crotts, M. Zaldarriaga.
  PDF-copy from the e-print ArXiv:astro-ph/0309204.
• Imprints of short distance physics on inflationary cosmology
  R. Easther, B. R. Greene, W. H. Kinney, G.Shiu; Phys. Rev. D67, 063508 (2003).
  PDF-copy from the e-print ArXiv:hep-th/0110226.
• All articles by ISCAP members from the SPIRES high-energy physics database.