Join us on Thursday, April 23rd for our first installment of our Spring Physics Colloquia Series!

 

Guest lecturer, Dr. Mathew Madhavacheril, will be visiting from the University of Pennsylvania and present his talk "Cosmic consistency tested over 12 billion years".

 

Abstract:

The oldest light we have access to, the cosmic microwave background (CMB), has allowed us to build a standard cosmological model based on well-understood physics, albeit with uncharacterized ingredients like dark matter.  This model makes predictions for how structures grow under gravity over its nearly 14 billion year history. A variety of cosmological observables offer independent and complementary ways of testing these predictions, but results have been mixed, with many constraints on the amplitude of matter fluctuations being 5-10% lower than the early-universe extrapolated expectation. Could this be due to new physics like a possible galaxy-scale de Broglie wavelength of ultralight dark matter? Or could this be due to complexities like feedback from active galaxies?   I will show how measurements of gravitational lensing of the CMB (together with other scattering effects) has and will continue to provide insights into this problem. Highlighting new results, I will sketch how the new Simons Observatory plans to make progress on these and related questions.

 

Can't make it? Join us on Zoom!

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