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Add to Calendar 11/16/2018 12:00 pm 11/16/2018 America/Chicago High Energy Phenomenology Seminar: Nikita Blinov, "Cosmology with Sub-MeV Thermal Relics" DESCRIPTION:

The nature of dark matter (DM) is unknown, with a vast array of possibilities able to 

account for the missing mass of the universe. A predictive subset of DM models has 

DM in thermal equilibrium with Standard Model particles in the early universe. 

A well-known example of this is the Weakly-Interacting Massive Particle (WIMP) with an electroweak-scale mass. 

However, as direct searches for WIMP-nucleus interactions set stronger and stronger limits, 

attention has turned to less well-explored DM candidates. Sub-MeV thermal relics, in particular, 

have received little attention, in part due to the apparently stringent bounds from astrophysics and cosmology.

For example, such particles contribute to the energy density of the universe at the time

of nucleosynthesis and recombination. The resulting constraints on extra degrees of freedom typically

exclude even the simplest of such dark sectors. I will describe the physics that leads to these bounds and show that if a sub-MeV dark sector entered equilibrium with the Standard Model after neutrino-photon decoupling, these constraints are alleviated. 

This scenario naturally arises in theories of neutrino mass generation through the

spontaneous breaking of lepton number. Dark matter relic abundance in these models independently

motivates the MeV scale. This scenario will be decisively tested

by future measurements of the cosmic microwave background and large scale structure of the universe.

\n\nSPEAKER:

Nikita Blinov (Fermilab)

Loomis 464

false

High Energy Phenomenology Seminar: Nikita Blinov, "Cosmology with Sub-MeV Thermal Relics"

Speaker Nikita Blinov (Fermilab)
Date: 11/16/2018
Time: 12 p.m.
Location:

Loomis 464

Event Contact: Lauren Pearce
lpearce@illinois.edu
Sponsor:

High Energy & Cosmo Theory

Event Type: Seminar/Symposium
 

The nature of dark matter (DM) is unknown, with a vast array of possibilities able to 

account for the missing mass of the universe. A predictive subset of DM models has 

DM in thermal equilibrium with Standard Model particles in the early universe. 

A well-known example of this is the Weakly-Interacting Massive Particle (WIMP) with an electroweak-scale mass. 

However, as direct searches for WIMP-nucleus interactions set stronger and stronger limits, 

attention has turned to less well-explored DM candidates. Sub-MeV thermal relics, in particular, 

have received little attention, in part due to the apparently stringent bounds from astrophysics and cosmology.

For example, such particles contribute to the energy density of the universe at the time

of nucleosynthesis and recombination. The resulting constraints on extra degrees of freedom typically

exclude even the simplest of such dark sectors. I will describe the physics that leads to these bounds and show that if a sub-MeV dark sector entered equilibrium with the Standard Model after neutrino-photon decoupling, these constraints are alleviated. 

This scenario naturally arises in theories of neutrino mass generation through the

spontaneous breaking of lepton number. Dark matter relic abundance in these models independently

motivates the MeV scale. This scenario will be decisively tested

by future measurements of the cosmic microwave background and large scale structure of the universe.

To request disability-related accommodations for this event, please contact the person listed above, or the unit hosting the event.

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