Solving the Hierarchy Problem with Noncompact Extra Dimensions

We show that gravitational effects of global cosmic 3-branes can be responsible for compactification from six to four space-time dimensions, naturally producing the observed hierarchy between electroweak and gravitational forces. The finite radius of the transverse dimensions follows from Einstein's equation, and is exponentially large compared with the scales associated with the 3-brane. The space-time ends on a mild naked singularity at the boundary of the transverse dimensions; nevertheless unitary boundary conditions render the singularity harmless.Comment: 11 pages. Several references adde

Optimized gyrosynchrotron algorithms and fast codes

Gyrosynchrotron (GS) emission of charged particles spiraling in magnetic fields plays an exceptionally important role in astrophysics. In particular, this mechanism makes a dominant contribution to the continuum solar and stellar radio emissions. However, the available exact equations describing the emission process are extremely slow computationally, thus limiting the diagnostic capabilities of radio observations. In this work, we present approximate GS codes capable of fast calculating the emission from anisotropic electron distributions. The computation time is reduced by several orders of magnitude compared with the exact formulae, while the computation error remains within a few percent. The codes are implemented as the executable modules callable from IDL; they are made available for users via web sites.Comment: Proceedings of the IAU Symposium 274 "Advances in Plasma Astrophysics

Pocket Gopher (\u3ci\u3eGeomys bursarius\u3c/i\u3e) Disturbance on a Tallgrass Prairie in Central Nebraska

The amount of deposited soil from pocket gopher (Geomys bursarius) mounds was quantified on a tallgrass prairie. Five percent of the total surface area was covered by mounds and the rate of mound formation was highest in early October at 64.57 mounds/ha/day. Mound-building activity and air temperature were not significantly related