Hal Finkel

With the recent progress in gravitational-wave detector development there has been considerable interest in calculating gravitational-wave observables. Inflation has long been known to generate a stochastic background of gravitational waves, with a largely featureless spectrum. A popular termination mode for inflation models is a process known as preheating, which uses a parametric resonance to transfer energy into a specific set of momentum modes of fields. It has been recently shown that a large class of inflation models involving preheating produce a potentially-detectable gravitational-wave signal peaked in the MHz range. These signals, caused by the "classical" density perturbation quadrupole moment, do not have a scale-free spectrum and would shed important information on the phase transition at the end of inflation.

Over the past few months, I have been working on extending the computer codes used to compute the gravitational-wave spectrum from a class of preheating inflation models to run on Beowulf-style clusters using the MPI library interface. This is necessary in order to probe a wider range of wavelengths than those accessible using the single-processor code. The limited lattice size did not allow the long-wavelength tail of the signal spectrum to be fully resolved. It is expected that at super-horizon scales, the power spectrum should undergo a steep decline, and this feature is calculable with a larger lattice. Currently, the MPI-enabled version of the code is undergoing testing. Also, I have been working on a new field-evolution code.

For additional background, see: Richard Easther and Eugene A. Lim "Stochastic Gravitational Wave Production After Inflation," JCAP 0604, 2006

Finkel, Hal J., Markoff, D. M., et al. "Analysis of High Rate Photomultiplier Tubes in KamLAND," Division of Nuclear Physics Fall Meeting, Poster Session (8P), (Tucson, Arizona, USA: 31 Oct. 2003)

Finkel, Hal J. "Stochastic Evolution of Graphs using Local Moves," LOOPS'05, (Potsdam, Germany: 13 Oct. 2005)

Finkel, Hal J. "Stochastic Evolution of Graphs using Local Moves," arXiv:hep-th/0601163