Conveners
Workshop on Dark matter from micro to macro
- Elena Arbuzova (Dubna State University and Novosibirsk State University)
Workshop on Dark matter from micro to macro
- Andrej Arbuzov (Joint Institute for Nuclear Research)
Workshop on Dark matter from micro to macro
- Rute Pedro (Laboratory of Instrumentation and Experimental Particle Physics (PT))
Workshop on Dark matter from micro to macro
- Michael Eides (University of Kentucky)
Workshop on Dark matter from micro to macro
- David Kapukchyan (University of California, Riverside)
Workshop on Dark matter from micro to macro
- Elena Arbuzova (Dubna State University and Novosibirsk State University)
In 2005 we predicted that based on VLBI observations it would be possible reconstruct a small dark spot (shadow) at the Galactic Center. Using current available estimates for distance and mass of the black hole we evaluated the shadow diameter as 50 μas.
Later, the Event Horizon Telescope Collaboration observations and its data analysis have confirmed our predictions. Really, in 2019 the...
Primordial black holes (PBHs) are a promising candidate for the dark matter in the universe. We present mechanisms that produce large density fluctuations that lead to the formation of dark matter PBHs. As PBH formation models, we consider multi-field inflation, the axion-like curvaton model, and the non-topological soliton model.
The gravitational lensing parallax of gamma-ray bursts (GRB), also known as picolensing, is a promising probe of compact dark matter, such as primordial black holes (PBH). A future space mission consisting of two X-ray/gamma-ray detectors in the Swift/BAT class can probe PBHs in the asteroid-mass window — a range of masses that has been notoriously hard to constrain by any other means. I will...
For decades, we have been looking for Dark Matter in the form of WIMPs, but many other possibilities exist. Light DM, intended as having a mass between 1 MeV and about 1 GeV, is one of these possibilities, which is interesting both theoretically and phenomenologically. Testing it via Indirect Detection is more challenging than WIMPs, but X-ray measurements provide a very powerful handle. They...
The potential resolution of the problem of theoretically predicted
excessive $^7$Li abundance is explored through its destruction by nucleons emitted from evaporating primordial black holes. It is demonstrated that the $^7$Li-to-baryon number density ratio can be reduced to the observed value of $^7$Li/B $\sim 1.6 \times 10^{-10}$ by converting $^7$Li into $^8$Li or $^8$Be, both of which...
The spatial distribution of galaxies (as a sample of gravitational sources)
mainly reveals voids, whose walls are made up of sheets and filaments. Due
to their size, these structures are the most representative for the study of
cosmological expansion. I analyze how the expansion dynamics of an un-
derdense (or even empty) region in the Universe can be used to determine
the values of...
Recent precise measurements of the primordially produced D and He-4 allowed us to update the BBN constraints on electron-sterile neutrino oscillations parameters. We discuss lepton asymmetry - neutrino oscillations interplay and derive cosmological constraints on lepton asymmetry. We discuss a solution to the dark radiation (DR) problem in BBN models with electron-sterile neutrino...
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It is usually assumed that supermassive black holes (SMBH) are created by matter accretion to excessive
density in galactic centers. However, the estimated necessary time is by far longer than the age of the universe. Moreover, SMBHs are observed also in the early universe, when the available time is much shorter. These and
plenty of other facts present strong evidence in favor...
Quantum effects during the epoch of the universe reheating after inflation are considered. A semiclassical approach to the theory of gravity is applied in connection with the Starobinsky inflation model. Some subtleties associated with taking into account quantum effects in the one-loop approximation are clarified. An estimate of the contribution of vacuum polarization in the energy-momentum...
Invited talk
We show for the first time that warm inflation is feasible with Standard Model (SM) gauge interactions alone. Our model consists of a minimal extension of the SM by a single scalar inflaton field with an axion-like coupling to gluons and a monomial potential. The effects of light fermions, which were previously argued to render warm inflation with the SM impossible, are alleviated by Hubble...
Primordial black holes are black holes that may have formed in the early Universe. Their masses potentially span a range from as low as the Planck mass up to many orders of magnitude above the solar mass. This, in particular, includes those black holes recently discovered through gravitational waves, and (part of) these may conceivably be of primordial origin. After a general introduction on...
We discuss equilibration process in expanding universes as compared to the thermalization process in Minkowski space--time. The final goal is to answer the following question: Is the equilibrium reached before the rapid expansion stops and quantum effects have a negligible effect on the background geometry or stress--energy fluxes in a highly curved early Universe have strong effects on the...
