254 citations · 832 across the 32 of their papers we have counts for
29 papers · 1 filter
The pre-infall bias of subhalos
M. Sten Delos, Andrew Benson
Dark matter halos destined to fall into a more massive host differ from typical field halos of the same mass even before infall. In cosmological simulations, we find that the proge…
Warm, not Fuzzy: Generalized Ultralight Dark Matter Limits from Milky Way Satellites
Ethan O. Nadler, Mustafa A. Amin, Risa H. Wechsler +3
We generalize lower limits on the dark matter (DM) particle mass derived from Milky Way (MW) satellite galaxy abundances to scenarios in which DM is an ultralight scalar field…
Testing warm dark matter with kinematics of the smallest galaxies
M. Sten Delos, Niusha Ahvazi, Andrew Benson
Every dark matter halo forms with a density cusp at its center. For warm dark matter (WDM), these prompt cusps can be massive enough to influence the kinematics…
Growth of Structure in Multi-species Wave Dark Matter
Mustafa A. Amin, M. Sten Delos
We explore the growth of structure in multi-species wave (and particle) dark matter. We derive the evolution of the power spectrum of total density contrasts for an arbitrary numbe…
Multi-species Dark Matter with Warmth and Randomness
Mustafa A. Amin, M. Sten Delos, Kaixin Yang
We present a general analytic framework for the evolution of cosmic structure in multi-species dark matter models that simultaneously incorporates finite velocity dispersion and Po…
The cusp-halo relation
M. Sten Delos
Simulations have established that each halo of collisionless dark matter is expected to contain a density cusp at its center. This prompt cusp is a relic of the hal…
Structure Formation with Warm White Noise: Effects of Finite Number Density and Velocity Dispersion in Particle and Wave Dark Matter
Mustafa A. Amin, M. Sten Delos, Mehrdad Mirbabayi
We investigate the evolution of density perturbations in dark matter, including the new combined effects of finite number density and non-zero velocity dispersion. Using a truncate…
21-cm Constraints on Dark Matter Annihilation after an Early Matter-Dominated Era
Hwan Bae, Adrienne L. Erickcek, M. Sten Delos +1
Although it is commonly assumed that relativistic particles dominate the energy density of the universe quickly after inflation, a variety of well-motivated scenarios predict an ea…
Conversations and Deliberations: Non-Standard Cosmological Epochs and Expansion Histories
Brian Batell, Keith R. Dienes, Brooks Thomas +17
This document summarizes the discussions which took place during the PITT-PACC Workshop entitled "Non-Standard Cosmological Epochs and Expansion Histories," held in Pittsburgh, Pen…
Structure formation with primordial black holes: collisional dynamics, binaries, and gravitational waves
M. Sten Delos, Antti Rantala, Sam Young +1
Primordial black holes (PBHs) could compose the dark matter content of the Universe. We present the first simulations of cosmological structure formation with PBH dark matter that…
Limits on Early Matter Domination from the Isotropic Gamma-Ray Background
Himanish Ganjoo, M. Sten Delos
In cosmologies with hidden sector dark matter, the lightest hidden sector species can come to dominate the energy budget of the universe and cause an early matter-dominated era (EM…
Accurate halo mass functions from the simplest excursion set theory
M. Sten Delos
Excursion set theory is a powerful and widely used tool for describing the distribution of dark matter haloes, but it is normally applied with simplifying approximations. We use nu…
Can prompt cusps of WIMP dark matter be detected as individual gamma-ray sources?
M. Sten Delos
Prompt density cusps are the densest and most abundant dark matter systems. If the dark matter is a weakly interacting massive particle (WIMP), recent studies h…
Simulations of Gravitational Heating Due to Early Matter Domination
Himanish Ganjoo, M. Sten Delos
In cosmologies with an early matter-dominated era (EMDE) prior to Big Bang nucleosynthesis, the boosted growth of small-scale matter perturbations during the EMDE leads to microhal…
How an era of kination impacts substructure and the dark matter annihilation rate
M. Sten Delos, Kayla Redmond, Adrienne L. Erickcek
An era of kination occurs when the Universe's energy density is dominated by a fast-rolling scalar field. Dark matter that is thermally produced during an era of kination requires…
Massive prompt cusps: A new signature of warm dark matter
M. Sten Delos
Every dark matter halo and subhalo is expected to have a prompt central density cusp, which is a relic of its condensation out of the smooth mass distribution o…
Lensing constraints on ultradense dark matter halos
M. S. Delos, G. Franciolini
Cosmological observations precisely measure primordial variations in the density of the Universe at megaparsec and larger scales, but much smaller scales remain poorly constrained.…
Ultradense dark matter haloes accompany primordial black holes
M. Sten Delos, Joseph Silk
Primordial black holes (PBHs) form from large-amplitude initial density fluctuations and may comprise some or all of the dark matter. If PBHs have a broadly extended mass spectrum,…
Prompt cusps and the dark matter annihilation signal
M. Sten Delos, Simon D. M. White
As the first dark matter objects gravitationally condense, a density cusp forms immediately at every initial density maximum. Numerical simulations and theoretical arguments sugges…
Inner cusps of the first dark matter haloes: Formation and survival in a cosmological context
M. Sten Delos, Simon D. M. White
We use very high resolution cosmological zoom simulations to follow the early evolution of twelve first-generation haloes formed from gaussian initial conditions with scale-free po…
Dark Matter Microhalos in the Solar Neighborhood: Pulsar Timing Signatures of Early Matter Domination
M. Sten Delos, Tim Linden
Pulsar timing provides a sensitive probe of small-scale structure. Gravitational perturbations arising from an inhomogeneous environment could manifest as detectable perturbations…
The First Three Seconds: a Review of Possible Expansion Histories of the Early Universe
Rouzbeh Allahverdi, Mustafa A. Amin, Asher Berlin +23
It is commonly assumed that the energy density of the Universe was dominated by radiation between reheating after inflation and the onset of matter domination 54,000 years later. W…
Breaking a dark degeneracy: The gamma-ray signature of early matter domination
M. Sten Delos, Tim Linden, Adrienne L. Erickcek
The Universe's early thermal history is poorly constrained, and it is possible that it underwent a period of early matter domination driven by a heavy particle or an oscillating sc…
Evolution of dark matter microhalos through stellar encounters
M. Sten Delos
In the cold dark matter scenario, the smallest dark matter halos may be earth mass or smaller. These microhalos would be the densest dark matter objects in the Universe, making the…