Department of Physics & Astronomy
University of New Mexico

Physics and Astronomy Colloquium

Dark Matter as a Probe of the Very Early Universe

Presented by Dr. Rouzbeh Allahverdi, UNM, Physics and Astronomy

There are various lines of evidence that most of the matter in the universe is not luminous. However, the identity of dark matter remains as a major problem at the interface of cosmology and particle physics. The worldwide experimental searches for dark matter have largely focused on weakly interacting massive particles (WIMPs). The correct dark matter abundance may be nicely explained via "WIMP miracle" that assumes the universe was in thermal equilibrium when it was a tiny fraction of a second old. However, this paradigm is coming under increasing pressure in light of recent experimental data. Moreover, due to the lack of direct observational probe, thermal equilibrium of the universe at times much earlier than one second is an assumption.

In this talk, I discuss an alternative scenario for non-thermal production of dark matter. In a class of well-motivated particle physics models, the early universe went through an epoch of early matter domination due to dominance of non-relativistic heavy particles. Decay of these particles prior to one second, in addition to forming a thermal bath of the known elementary particles , could be the source of the observed dark matter abundance. I discuss the interesting opportunities that this scenario brings about as well as some challenges for its successful realization within explicit models.

3:30 pm, Friday, November 9, 2018
Room 125, Dane Smith Hall
Southwest corner of Las Lomas and Yale, Albuquerque, New Mexico

Refreshments will be available before the colloquium, at 3:15 pm, in the lobby of Dane Smith Hall.

Disability NoticeIndividuals with disabilities who need an auxiliary aid or service to attend or participate in P&A events should contact Sandra Ortiz (phone: 505-277-5900, email: well in advance to ensure your needs are accomodated. Event handouts can be provided in alternative accessible formats upon request. Please contact Mrs. Ortiz if you need written information in an alternative format.

A schedule of talks within the Department of Physics and Astronomy is available on the P&A web site at