I will explain recent work with S. Mizera in which we give explicit evaluations of one-loop open string amplitudes at finite alpha’. Our method involves various deformations of the contour integral over the modular parameter. We directly verify that the one-loop string amplitude satisfies unitarity constraints. I…

In this talk I will focus on light dark matter particles, with a mass between 1 MeV and a few GeV. These particles can annihilate or decay into electron-positron pairs which can upscatter the low-energy fields in our Galaxy and produce X-ray emission. By using the X-ray data from XMM-Newton, Integral, Suzaku and NuStar, we derive strong…

While Laughlin identified the fractional quantum Hall state as a consequence of an “incompressible quantum fluid”, well-described by his model  wavefunction  which exhibits “flux attachment”, no fundamental explanation of the energetics driving “flux attachment” has emerged. A new picture reveals that  a…

The search for low-dimensional topological superconductivity is fueled by the promise of new and exotic physics, such as chiral superconductivity and non-Abelian anyons. However, the need to break time-reversal symmetry, usually by applying a relatively large external magnetic field, has hindered the realization of these novel phases of matter…

A long standing problem in lattice QCD is to construct an explicit instanton density operator on the lattice. We introduce such a construction, after suitably refining the lattice Yang-Mills action, so that it captures the continuum Yang-Mills theory better than the traditional lattice Yang-Mills action does. This refinement needed follows…

I give new results for  “gravastars'', which are horizonless compact objects that closely mimic mathematical black holes in their exterior geometry,  but for which g_{00} is always positive.  They result from  solving the  Tolman-Oppenheimer-Volkoff  (TOV) equations for relativistic stellar structure, which require…

I will describe the correlators of fermion bilinears in the n-flavor massless Schwinger model. These are exactly calculable generalized free theories. For n > 1, there is a massive particle and a conformal sector. I have argued that in the n = 2 theory, very special mass terms can be added to introduce interactions…

We consider a model of Parisi where a single particle hops on an infinite-dimensional hypercube, under the influence of a uniform but disordered magnetic flux.  We reinterpret the hypercube as the Fock-space graph of a many-body Hamiltonian, and the flux as a frustration of the return amplitudes in Fock space. We…

The Atacama Cosmology Telescope is a ground-based CMB survey that has mapped half the millimeter sky at significantly higher resolution and sensitivity than the Planck satellite. I will present new ACT results from a 9400 sq.deg. gravitational lensing mass map, including constraints on the amplitude of matter fluctuations as well as the Hubble…

Studying non-abelian anyons is exciting due to their unique braiding statistics. The 5/2 quantum Hall state has been long proposed to host such localized quasiparticles in the 2D bulk. Resting on ‘bulk-edge’ correspondence, their gapless edge modes are expected to mirror the topological order of the 5/2 quantum state. Supporting an odd number…

The actomyosin cytoskeleton is a naturally occurring active gel found in virtually all mammalian cells. Its ability to contract allows cells to move, change shape, exert force, sense stiffness, and maintain constant tension. In order for the “hardware” of actomyosin gels to support such a diverse set of mechanical tasks, it is tightly coupled…

In this talk, I present different machine learning and data driven techniques that produce measurements of stellar kinematics around the Milky Way, and relate them to our understanding of Dark Matter. More specifically, I will discuss a data driven technique applied to Gaia DR3 combined with Apogee data to produce the circular velocity…