Research Poster Session - 2009
The Tuesday, December 1, 2009 open night at Ladd Observatory will feature a poster session by Brown University graduate students and faculty who will inform our visitors about the research that they are doing in astronomy, astrophysics, planetary sciences and cosmology. Ladd will be open this night regardless of the weather from 7-9 pm. There will also be telescope observing, if the weather permits. Please join us this evening to learn about the exciting research that is being conducted in the Departments of Physics, Geological Sciences and Applied Mathematics. Sponsored by the Department of Physics and the RI Space Grant Consortium.
The LUX Dark Matter Detection Experiment
Jeremy Chapman & James Verbus - (Gaitskell Group)
LUX will be deployed at the Sanford Underground Science and Engineering Laboratory (SUSEL) at the Homestake Mine 4850ft below the surface in Lead, SD. When it turns on LUX will be the most sensitive dark matter experiment in the world.
Weak Gravitational Lensing
Paul Huwe & Prof. Ian Dell'Antonio - (Dell'Antonio Group)
Einstein's Theory of General Relativity predicts that gravity bends light. A consequence of this is that large groups of mass will bend light, acting as a lens for whatever lays behind them. This effect, referred to as gravitational lensing, enables studies of numerous astronomical phenomenon - distant objects, dark matter studies, and mass properties.
The Role of Shear in Oblique Impacts
Angela Stickle - (Shultz Group)
Though extension plays a significant role in impact induced damage, it is also necessary to consider the role of shear failure as an important process that is observed at a variety of scales during and after impacts. Results from experiments performed at the NASA Ames Vertical Gun Range at the NASA Ames Research Center are compared to CTH hydrocode models to determine regions of shear and extensional failure in a variety of targets. Final damage patterns reveal large regions beneath the impact failing in shear, as well as significantly asymmetric structures. This has important implications for large impacts into planetary bodies such as the moon and mars, and provides insight into the subsequent internal damage and structures created by the impact.
Numerical General Relativity and Astrophysics
Scott Field
Realistic descriptions of astrophysical phenomena often requires the use of computer simulations. For example, to study gravitational waves, fluctuations in space itself, one must solve Einstein's equations of general relativity. These equations cannot be solved using a paper and pencil approach, thus one must rely on accurate computer models to gain insight into the information content carried by these waves. Our research is focused on designing a new class of accurate and efficient computer algorithms for such problems.
Bolometric Interferometry of Cosmic Microwave Background
Andrei Korotkov & Prof. Greg Tucker - (Tucker Group)
Observation of Cosmic Microwave Background (CMB) provides a direct window on the Universe at its very early formation stage. Detailed characterization of the CMB polarization has the potential to greatly advance our understanding of cosmology. Detection of large-scale pseudoscalar "B-component" of CMB polarization would provide direct evidence of primordial gravitational waves during inflation and even measure the inflationary energy scale. Bolometric interferometers combine the advantages of interferometers and high sensitivity of bolometers in order to measure this tiny B-mode signal.
The nature of dark matter
Alex Geringer-Sameth & Prof. Savvas Koushiappas (Koushiappas Group)
Dark matter constitutes 85% of the matter density of the Universe. In order to understand its nature, we must first invent physical models which reproduce observations, and then design experimental techniques that can test these models. The most promising candidate for the dark matter is a Weakly Interacting Massive Particle. Annihilation between dark matter particles leads to the emission of gamma-ray photons. Experiments like the Fermi Gamma-ray Space Telescope are capable of testing this hypothesis by searching for the annihilation signal. Even though the emission from dark matter may be extremely small, it may be possible to extract a signal out of a noisy background. We present novel statistical techniques that can be used to detect a time-dependent background signal. These techniques can be applied to many large area survey background experiments.
The E and B Experiment: Probing the Inflationary Gravitational Background Through Measurements of the Cosmic Microwave Background Radiation
Jerry Vinokurov - (Tucker Group)
The EBEX project seeks to measure the polarization anisotropy of the cosmic microwave background (CMB). The CMB is predicted to be linearly polarized due to Thomson scattering in the early universe, and the polarization field can be decomposed into curl- and divergence-free modes analogous to electromagnetic fields and known as E and B modes.
The B modes of the CMB polarization field are predicted to arise as a consequence of tensor perturbations, such as gravity waves. Measuring the primordial B-mode signal would provide a direct signature of the gravitational background at the time of inflation.