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Physics Colloquium: Propagation of Primordial Gravitational Waves in Cosmology |
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| Category: | College Of Engineering - Phy | |
| Date & Time: |
Wednesday, 10/17/2012 from 02:00 PM to 03:00 PM |
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| Location: | Seng 102 | |
| Admission: | Free! | |
| Contact: |
Robert Fisher rfisher1@umassd.edu 508-999-8353 |
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| Description: | Subhir Sabharwal Arizona State University Physics Department Title: Propagation of Primordial Gravitational Waves in Cosmology Abstract: In this talk, I will begin with a review of basic cosmology, then move onto cosmological perturbation theory focusing on the dynamics of ripples in the spacetime fabric, or gravitational waves. I will briefly demonstrate how gravitational waves are believed to be created in the very early universe through a process known as inflation. I will discuss the propagation of these primordial gravitational waves through this early epoch to the present. We will see that the waves are damped when they encounter free-streaming matter, primarily neutrinos. To study this, I will apply Boltzmann equation as relevant for early universe cosmology. I will then specifically look at the effect of a small neutrino mass and explore possible additional neutrino species (which,based on current cosmological bounds may number around 3.5). Finally, I will also show some (preliminary) results on damping of the tensor power spectrum from its expected inflation value that could have observational consequences for the Planck satellite. | |
