The braneworld model of Dvaliâ€“Gabadadzeâ€“Porrati (DGP) is a theory where gravity is modified at large distances by the arrested leakage of gravitons off our four-dimensional universe. Cosmology inâ€¦ (More)

Cosmologists today are confronted with the perplexing reality that the universe is currently accelerating in its expansion. Nevertheless, the nature of the fuel that drives todayâ€™s cosmicâ€¦ (More)

Although nonsingular spacetimes and those containing black holes are qualitatively quite different, there are continuous families of configurations that connect the two. In this paper we useâ€¦ (More)

We present new analytic and numerical results for self-gravitating SU(2)Higgs magnetic monopoles approaching the black hole threshold. Our investigation extends to large Higgs self-coupling, Î», aâ€¦ (More)

Are there any manifestations of parity violation other than those observed in weak interactions? A map of the cosmic microwave background (CMB) temperature and polarization will provide a newâ€¦ (More)

The nature of the fuel that drives todayâ€™s cosmic acceleration is an open and tantalizing mystery. We entertain the suggestion that the acceleration is not the manifestation of yet another newâ€¦ (More)

Observations exploring the contemporary cosmic acceleration have sparked interest in dark energy models possessing equations of state with w < âˆ’1. We review how the cosmic expansion history of aâ€¦ (More)

We present a model with an infinite volume bulk in which a braneworld with a cosmological constant evolves to a static, 4-dimensional Minkowski spacetime. This evolution occurs for a generic class ofâ€¦ (More)

If the graviton possesses an arbitrarily small (but nonvanishing) mass, perturbation theory implies that cosmic strings have a nonzero Newtonian potential. Nevertheless in Einstein gravity, where theâ€¦ (More)

Explaining the effects of dark matter using modified gravitational dynamics (MOND) has for decades been both an intriguing and controversial possibility. By insisting that the gravitationalâ€¦ (More)