Light scalar dark matter fields can exhibit several interesting aspects to their cosmological evolution. I will focus mostly on structure formation with ultralight axions and with the QCD axion. The standard scenario leads to a *suppression* of structure on small scales.

# Events Archive

## 2019

### Physics Group Meeting at IAS | Ken Van Tilburg, Member, School of Natural Sciences, IAS; NYU | “Formation of compact structures with axion dark matter”

### These Vibes are Too Cosmic - 103.3FM

### Pheno & Vino Seminar | Harikrishnan Ramani, Berkeley | "Pulsar timing probes of substructure" | Jadwin 303

Pulsars act as accurate clocks, sensitive to gravitational redshift and acceleration induced by transiting clumps of matter. We study the sensitivity of pulsar timing arrays (PTAs) to single transiting compact objects, focusing on primordial black holes and compact subhalos in the mass range from 10−12 Msun to well above 100 M sun.

### HET Seminar | Anatoly Dymarsky, University of Kentucky | "Generalized Eigenstate Thermalization in 2d CFTs”

Infinite-dimensional conformal symmetry in two dimensions equips 2d CFTs with an integrable structure - an infinite tower of quantum KdV charges in involution.

### Gravity Initiative Lunch, Adam Levine | UC Berkeley “Integrated Bounds on Null Energy in Semi-Classical Gravity”

Adam Levine (UC Berkeley) will be giving the lunch talk next Monday (12:30 pm, Jadwin 111).

Please sign up here if you would like to be included in the (free) lunch order: https://goo.gl/forms/GCT1UqQwlz9iGwgU2

### Biophysics Seminar: Jose Onuchic, Rice University| "The three-dimensional architecture of the human genome: understanding the physical mechanisms controlling gene expression"| Joseph Henry Room

In vivo, the human genome folds into a characteristic ensemble of 3D structures. The mechanism driving the folding process remains unknown. A theoretical model for chromatin (minimal chromatin model) that explains the folding of interphase chromosomes and generates chromosome conformations consistent with experimental data will be presented.

### Gravity Group Lunch Seminar, Max Abitbol | Oxford "Foregrounds of CMB B-modes and spectral distortions"

I will discuss topics related to foregrounds of two different CMB science cases. For the first part, I will introduce an expansion to foreground SED parameterizations in terms of moments of the parameter distributions.

### The Gravity Initiative Inaugural Meeting | PCTS Fourth Floor

**The Princeton Gravity Initiative** was founded to elevate local research exploring the mysteries of gravity across the disciplines of mathematics, physics and astrophysics.

### These Vibes are Too Cosmic - 103.3FM

### Pheno & Vino Seminar | Kim Boddy, Johns Hopkins | "Searching for Dark Matter Interactions in Cosmology" | Jadwin 303

There is a substantial effort in the physics community to search for dark matter interactions with the Standard Model of particle physics.

### HET Seminar at IAS | Samir Mathur, Ohio State University | “The Fuzzball Paradigm for Black Holes and Its Possible Implications for Cosmology”

In 1975 Hawking showed that the evaporation of black holes creates a problem for unitarity. This argument can be made rigorous through the small corrections theorem, and implies that there must be a fundamental change in our picture of semiclassical gravity. In string theory it appears that black hole microstates are horizon sized quantum...

### Gravity Initiative Lunch, Sean McWilliams | WVU

**Title: Analytic black-hole binary mergers: waveforms and kicks from first principles**

Please sign up here if you would like to be included in the (free) lunch order.

### HET Seminar | Zohar Komargodski, Stony Brook University | "Baryons as Quantum Hall Droplets"

We revisit the problem of baryons in the large N limit of Quantum Chromodynamics. A special case in which the theory of Skyrmions is inapplicable is one-flavor QCD, where there are no light pions to construct the baryon from. More generally, the description of baryons made out of predominantly one flavor within the Skyrmion model is...

### Gravity Group Lunch Seminar, Jo Dunkley | Princeton "Science forecasts for the Simons Observatory"

The Simons Observatory (SO) is a new CMB experiment being built in the Atacama Desert in Chile (with many contributions from Princeton) due to begin observations in the early 2020s.

### Hamilton Colloquium Series: Anthony Leggett, University of Illinois, "Why I don't believe that Quantum Mechanics is the Whole Truth", Jadwin A10

Not long after the birth of quantum mechanics nearly a century ago, Erwin Schroedinger pointed out, in his famous "Cat" paper, the difficulty which arises if we assume that the theory gives a complete account of the world up to and including our observations of it.

### Physics Group Meeting at IAS | Yvonne Geyer, Member, School of Natural Sciences, IAS | "6D Spinor-helicity and Superamplitudes"

I will give a review of recent progress in studying 6D SYM and supergravity amplitudes. Based on the spinor-helicity formalism of Cheung and O'Connell, recent work has shown that superamplitudes in 6D have a simple and compact form, not unlike 4D.

### These Vibes are Too Cosmic - 103.3FM

### Pheno & Vino Seminar | Glennys R. Farrar, NYU, "Pros and Cons of Sexaquark Dark Matter, and related topics" | Jadwin 303

A stable sexaquark is an appealing Dark Matter candidate. Simple statistical physics arguments, plus known QCD parameters (quark masses and QCD transition temperature), predicts the DM to baryon ratio after the QGP-hadron transition to be ~4.5 +- 1, in remarkable agreement with the observed value of 5.3 +- 0.1.

### HET Seminar at IAS | Kevin Costello, Perimeter Institute | "Twisted holography for the N=4 chiral algebra"

Beem et al.

### Gravity Initiative Lunch, Johan Samsing | Princeton

**Title:**Probing the origin of binary black hole mergers using multi-band GW observations and stellar tidal disruptions

Lunch will be provided, but to help economize the order please let us know if you want lunch by signing up.