Events at Physics
Events During the Week of October 20th through October 27th, 2019
- No events scheduled
- Chaos & Complex Systems Seminar
- A brief history of the soul from antiquity to integrated information theory
- Time: 12:05 pm
- Place: 4274 Chamberlin (refreshments will be served)
- Speaker: Peter Sobol, Wisconsin Public Media
- Abstract: The current interest in the nature of consciousness is only the latest episode in the long history of the Western world's efforts to understand awareness and intelligence. This talk will touch on the philosophical, medical, and religious problems that these efforts have encountered and will conclude with a survey of several different responses from contemporary philosophers and scientists to this still unanswered and perhaps unanswerable question.
- Host: Clint Sprott
- Theory Seminar (High Energy/Cosmology)
- TIME & LOCATION CHANGED!
- Axion Dark Matter Production and Sub-Structure in Non-Standard Cosmologies
- Time: 3:00 pm
- Place: 4274 Chamberlin Hall
- Speaker: Nikita Blinov, Fermilab
- Abstract: Ultra-violet completions of the Standard Model often feature a modified cosmology before Big Bang Nucleosynthesis. For example, the energy content of the universe prior to this epoch can be dominated by a non-relativistic particle that eventually decays and reheats the universe at temperatures of a few MeV. This period of early matter domination (EMD) has important consequences for both the amount of dark matter (DM) that is left over, and for the growth of density perturbations. I will discuss such a cosmology in the context of axion-like particle (ALP) dark matter, whose non-thermal nature makes it especially sensitive to these early-universe dynamics. EMD leads to qualitatively different target parameter space for direct detection experiments. I will also show that ALP density perturbations grow much faster during EMD, leading to the formation of dense DM clumps, or minihalos, with characteristic masses below the Earth mass. While extremely rare, Earth encounters with these clumps would lead to enhanced signals in direct detection experiments. These small-scale structures can also be probed with pulsar timing and photometric monitoring of highly magnified extragalactic stars.
- Host: Nicholas Orlofsky
- Cosmology Journal Club
- Time: 12:00 pm
- Place: 5242 Chamberlin Hall
- Abstract: Please visit the following link for more details:
Feel free to bring your lunch!
If you have questions or comments about this journal club, would like to propose a topic or volunteer to introduce a paper, please email Ross Cawthon (firstname.lastname@example.org) and Santanu Das (email@example.com).
- Astronomy Colloquium
- "Open Cluster Variables: Essential Astrophysical Probes"
- Time: 3:30 pm
- Place: 4421 Sterling Hall, Coffee and cookies 3:30 PM, Talk begins 3:45 PM
- Speaker: Melinda Soares, Princeton University
- Abstract: A layer of complexity is missing from the prevailing standard stellar evolution model. Peculiar stars, particularly those found in coeval, isometallic systems like open clusters, play a critical role in its refinement. The blending of stellar light in densely populated clusters poses a formidable challenge in the generation of high-precision light curves. To mitigate such concerns, our team produced an image subtraction pipeline that reveals a diverse population of periodic variables in the K2 dataset. This technique has unveiled new candidate exoplanets, eclipsing binaries, rapidly rotating stars, and pulsating variables. Moreover, we detect sources that are not revealed by other methods, indicating that the image subtraction technique is required to fully exploit cluster fields. I discuss the potential of utilizing cluster variables to probe critical open questions in stellar astrophysics.
- Host: Professor Robert Mathieu
- Physics Department Colloquium
- NO COLLOQUIUM 10/25/19
- Time: 3:30 pm
- Abstract: NO COLLOQUIUM 10/25/19