Abstract: TBA

I discuss well-motivated examples where Dark Matter production at the LHC can leave its imprint through striking visible signatures in addition to missing energy.

The fundamental properties of dark matter can affect structure formation in our Universe in subtle ways. Unfortunately, many dark matter theories make similar predictions for how structure assembles on large and small scales, leading to a large degeneracy in model space. Motivated by this, we formulate an effective theory of structure formation …

Precision gauge coupling unification is one of the primary quantitative successes of low energy or split supersymmetry. Preserving this success puts severe restrictions on possible matter and gauge sectors that might appear at collider-accessible energies. In this work we enumerate new gauge sectors which are compatible with unification,…

In this talk I will describe a new solution to the hierarchy problem, "Nnaturalness". Introducing a large N copies of the Standard Model with varying values of the Higgs mass parameter allows the lightest of these sectors to have a weak scale parametrically lighter than the cutoff. If we assume that the early universe is dominated by a "reheaton"…

In this talk, I'll quantify the challenge of explaining the baryon asymmetry using initial conditions in a universe that undergoes inflation. Contrary to lore, such an explanation is possible if net B−L number is stored in a light bosonic field with hyper-Planckian initial displacement and a delicately field velocity prior to inflation. However,…

We derive the latest constraints on various simplified models of natural SUSY with light higgsinos, stops and gluinos, using a detailed and comprehensive reinterpretation of the most recent 13 TeV ATLAS and CMS searches with $\sim 15$~fb$^{-1}$ of data. We discuss the implications of these constraints for fine-tuning of the electroweak scale. A…

The Weak Gravity Conjecture (WGC), in its original form, says that given an abelian gauge theory there should be at least one charged particle whose charge is bigger than its mass in Planck units. This has surprisingly powerful implications for the possibility of large-field inflation. In this talk I will discuss some of the arguments linking the…

Weakly Interacting Massive Particles (WIMPs) have been the main focus of the Dark Matter (DM) community for many years. However, there are both experimental clues and theoretical motivation to think beyond the WIMP paradigm and consider new ideas in the search for DM. I discuss two such new directions. First I explore a new low-threshold direct…

Particle production takes important rolls in the early universe, such as during inflation, preheating and reheating eras. I discuss particle production of many scalars or gauge bosons as slow roll mechanism. In particular, the effect is exponentially enhanced by cascade decays. Also, such particle production can be relevant to a recent idea,…

The LIGO detection of gravitational waves has opened a new window on the universe. I will discuss how the process of superradiance, combined with gravitational wave measurements, makes black holes into nature's laboratories to search for new light bosons. When a bosonic particle's Compton wavelength is comparable to the horizon size of a black…

Dark matter with MeV-to-GeV masses is a theoretically and phenomenologically interesting possibility. In this talk, I will describe how direct-detection experiments can probe this largely unexplored mass range. A particularly promising possibility is that dark matter scatters off electrons, causing ionization or excitation of atoms in a…

The morphology of dark matter annihilation/decay signals offers a handle for discrimination of dark matter against astrophysical backgrounds. Recent advances in N-body simulations allow us to map out the expected distribution of morphological parameters, rather than focusing on a small sample of halos which are assumed to be representative. In…

The lack of gluino signals in existing LHC data makes Dirac gauginos more motivated in weak scale SUSY phenomenology. I will describe a solution to a long-standing challenge in Dirac Gaugino model building, namely, how to avoid ubiquitous tachyons charged under the Standard Model gauge symmetries. I will also briefly discuss a simple realization…

PLEASE NOTE CHANGE IN LOCATION AND TIME -- 5:00 pm IN JADWIN A07. I will discuss a toy theory of gravity where the gravitational force is mediated by a scalar particle. This theory can be understood as the low-energy limit of a spontaneously broken Conformal Field Theory, and serves as an intriguing analog to General Relativity, capturing…

PLEASE NOTE CHANGE IN TIME & LOCATION FOR TODAY'S MEETING 5:00 Room: Jadwin A07 We analyze confining gauge theories where the 750 GeV diphoton resonance is a composite heavy pion that undergoes anomalous decays into SM vectors. These scenarios naturally contain accidentally stable pions Dark Matter candidates. The diphoton resonance can…

Jet substructure techniques have emerged as an essential tool for new physics searches at the LHC. In this talk, I highlight the ways that theoretical studies of jet substructure have revealed fascinating new phenomena in QCD. Using the Run 1 ATLAS diboson excess as motivation, I present jet substructure observables that blur the boundary…

If the dark matter is made up of a bosonic particle, it can be ultralight, with a mass potentially much below 1 eV. Moduli fields, whose values could set couplings and masses of known particles, are good candidates for such light dark matter. Their abundance in our Universe would manifest itself as tiny fractional oscillations of Standard Model…

Very little is known about cosmology away from the homogeneous limit. In this talk I will describe a set of results pertaining to universes with arbitrarily large inhomogeneity and anisotropy. I will prove rigorously that the spatial topology strongly constrains the ultimate fate of the universe - for “most” spatial topologies and with matter…

The ratio of the measured B → D(*) l nu decay rates for tau and lighter leptons deviate from the Standard Model (SM) by about 4 standard deviation. I will discuss why the data is in tension with SM predictions, independent of complications in modeling exclusive decays, and complementary measurements that can be made to reduce associated theory…