139 citations · 549 across the 9 of their papers we have counts for
9 papers
Gravitational Atoms
Niklas G. Nielsen, Andrea Palessandro, Martin S. Sloth
Particles in a yet unexplored dark sector with sufficiently large mass and small gauge coupling may form purely gravitational atoms (quantum gravitational bound states) with a rich…
Neutron Star Stability in Light of the Neutron Decay Anomaly
Benjamin Grinstein, Chris Kouvaris, Niklas Grønlund Nielsen
A recent proposal suggests that experimental discrepancies on the lifetime of neutrons can be resolved if neutrons decay to dark matter. At the same time it has been demonstrated t…
The Sun as a sub-GeV Dark Matter Accelerator
Timon Emken, Chris Kouvaris, Niklas Grønlund Nielsen
Sub-GeV halo dark matter that enters the Sun can potentially scatter off hot solar nuclei and be ejected much faster than its incoming velocity. We derive an expression for the rat…
The Spectrum of Darkonium in the Sun
Chris Kouvaris, Kasper Langaeble, Niklas Grønlund Nielsen
Dark matter that gets captured in the Sun may form positronium-like bound states if it self-interacts via light dark photons. In this case, dark matter can either annihilate to dar…
Boson Stars from Self-Interacting Dark Matter
Joshua Eby, Chris Kouvaris, Niklas Grønlund Nielsen +1
We study the possibility that self-interacting bosonic dark matter forms star-like objects. We study both the case of attractive and repulsive self-interactions, and we focus parti…
White Dwarf Critical Tests for Modified Gravity
Rajeev Kumar Jain, Chris Kouvaris, Niklas Grønlund Nielsen
Scalar-tensor theories of gravity can lead to modifications of the gravitational force inside astrophysical objects. We exhibit that compact stars such as white dwarfs provide a un…
Asymmetric Dark Matter Stars
Chris Kouvaris, Niklas Grønlund Nielsen
We study the possibility of asymmetric dark matter with self-interactions forming compact stable objects. We solve the Tolman-Oppenheimer-Volkoff equation and find the mass-radius…
Daily modulation and gravitational focusing in direct dark matter search experiments
Chris Kouvaris, Niklas Grønlund Nielsen
We study the effect of gravitational focusing of the earth on dark matter. We find that the effect can produce a detectable diurnal modulation in the dark matter signal for part of…
Inflation from Asymptotically Safe Theories
Niklas Grønlund Nielsen, Francesco Sannino, Ole Svendsen
We investigate models in which inflation is driven by an ultraviolet safe and interacting scalar sector stemming from a new class of nonsupersymmetric gauge field theories. These n…