Colloquium Feb 3, 2019 -- Illuminating the Early Universe with Dark Matter Minihalos

Adrienne Erickcek
University of North Carolina

Illuminating the Early Universe with Dark Matter Minihalos

There is strong observational evidence that the infant Universe experienced a period of accelerated expansion called inflation. Unfortunately, we do not know how inflation ended nor how the Universe evolved between the end of inflation and the onset of Big Bang nucleosynthesis (BBN). As remnants of the earliest stages of structure formation, the smallest dark matter halos provide a unique probe of the density fluctuations generated during the later stages of inflation and the evolution of the Universe shortly after inflation. The absence of early-forming ultra-compact minihalos (UCMHs) establishes an upper bound on the amplitude of the primordial power spectrum on small scales and has been used to constrain inflationary models. I will show how numerical simulations of UCMH formation reveal that these constraints need to be revised because the dark matter annihilation rate within UCMHs is lower than has been assumed. Nevertheless, we have found that minihalos can still provide unrivaled constraints on the small-scale primordial power spectrum. The abundance of minihalos also encodes information about the evolution of the Universe prior to BBN. I will discuss how the pre-BBN thermal history affects the minihalo population and the dark matter annihilation rate within dwarf spheroidal galaxies, making it possible to use gamma-ray observations to learn about the evolution of the Universe during its first second.

[quantumofspace]

The DARK ENERGY curtain is opening, gentlemen. Without fear of simplicity, imagine such a blooming UNIVERSE:
Quantum gravity is the vibrations of waves in a spherical quantum field. Or the wave pressure in the quantum membrane in the "rosebud", where the transfer of wave energy during the drift of the center in the "rosebud" is possible through the quantum of the string.
Quantum entanglement is a mixed transmission of information without intermediaries through the quantum of strings and with intermediaries in fractals from the quantum of "rosebuds".
The visible Universe is crumbling over the skeleton - Immeasurable a quantum of strings on which fractals grow, quantum "rosebuds" in the form of dark energy.

[AmjadObeidat]

Why is the audio so bad? Please put a good mic on these speakers!