Physicist and author at Fermilab and the University of Chicago
Oct 2, 2020 • 4 tweets • 1 min read
(1/4) As requested, here is the (provisional) reading list for my class on "Philosophical Problems in Cosmology".
1) Steven Weinberg, To Explain the World 2) Karl Popper, “Science: Conjectures and Refutations”
3)Thomas Kuhn, “The Logic of Discovery of Psychology of Research?”
(2/4) 4) A.J. Ayer, Language, Truth and Logic 5) Dan Hooper, At the Edge of Time 6) Sean Carroll, Something Deeply Hidden 7) Sean Carroll, “Why is there something rather than nothing?” 8) Sean Carroll, “Beyond Falsifiability: Normal Science in a Multiverse”
May 6, 2019 • 5 tweets • 2 min read
(1/5) I'm excited about a new paper that I've written with @GordanKrnjaic and Sam McDermott. It combines some of my favorite things: black holes, dark matter, and the Hubble tension. arxiv.org/abs/1905.01301 #blackholes#cosmology#darkmatter#Hubble
(2/5) If even a small number of black holes were created around the time of inflation, their relative abundance would grow as the universe expands, making it quite plausible that the energy density of the early universe was once dominated by black holes.
Mar 7, 2019 • 5 tweets • 2 min read
(1/5) Two papers came out this week arguing that there is a robust excess of ~10-20 antiprotons in the cosmic-ray spectrum. Among other reasons, this is exciting because it could be explained by annihilating dark matter.
(2/5) Furthermore, the dark matter mass and annihilation cross section that are required to produce this antiproton excess are the same as those that are required to produce the long-standing Galactic Center gamma-ray excess.
Jan 9, 2019 • 6 tweets • 2 min read
(1/6) My Collaborators (Miguel Escudero, @GordanKrnjaic and Mathias Pierre) and I just posted a new paper that I am excited about, "Cosmology With a Very Light L_mu - L_tau Gauge Boson", arxiv.org/pdf/1901.02010…
Let me take a minute to walk you through the main points. #cosmology
(2/6) We considered a new light particle, a Z' associated with a broken U(1)_mu-tau symmetry, and solved the full set of Boltmann equations to determine how such a particle would impact the energy density in neutrinos and other radiation in the early universe. #cosmology