**Monday, November 18, 2019**

Gravity Initiative Lunch

“Probing Near-Horizon Physics via Gravitational Wave Echoes”

Location: Jadwin Hall, Princeton Gravity Initiative, 4th Floor

Time: 12:30 PM

Speaker(s): Baoyi Chen, Caltech**Description:**Because of the Black-Hole Information Paradox, and the singularity, many physicists believed that GR must be modified to incorporate quantum effects, and that such modifications may affect black-hole spacetimes. The additional near-horizon structure might modify the boundary conditions for incoming gravitational waves, and lead to gravitational wave echoes. These echoes will then become the "smoking gun" of modifications to relativity. Therefore parametrizing gravitational echoes and searching for them will be an important way to quantify how "black" the black holes really are. In this talk, I will talk about the theoretic formulation of gravitational wave echoes, and point out the current issues associated with this idea.

**Monday, November 18, 2019**

High Energy Theory Seminar

“TMF and SQFT”

Location: Bloomberg Lecture Hall

Time: 2:30 PM

Speaker(s): Theo Johnson-Freyd, Perimeter Institute**Description:**I will describe my work, all joint with D. Gaiotto and some also joint with E. Witten, to understand the homotopy type of the space of (1+1)d N=(0,1) SQFTs --- what a condensed matter theorist would call "phases" of SQFTs. Our motivating hypothesis (due in large part to Stolz and Teichner) is that this space models the spectrum called "topological modular forms". Our work includes many nontrivial checks of this hypothesis. First, the hypothesis implies constraints on the possible values of elliptic genera, and suggests (but does not imply) the existence of holomorphic SCFTs saturating these constraints; we have succeeded in constructing such SCFTs in low central charge. Second, the hypothesis implies the existence of torsion-valued "secondary invariants" beyond the elliptic genus that protect SQFTs from admitting deformations that spontaneously break supersymmetry. I will explain such an invariant in terms of holomorphic anomalies and mock modularity.

**Tuesday, November 19, 2019**

Deep Learning for Physics

“Topic #1: Flows Three Ways; Topic #2: Deep Learning and String Theory”

Location: Jadwin Hall, Room 407

Time: 11:45 AM

Speaker(s): Kyle Cranmer, New York University, James Halverson, Northeastern University

Note: Each talk will be preceded with lunch at 11:45 am. The talks will be held from 12:25-1:30 pm. Please check the specific date for room location.**Description:****Registration for each event is free, but required. Please click on the registration link below for each date, as it becomes available.****Register here:**

https://docs.google.com/forms/d/e/1FAIpQLScD1ZGB17mwhZ3cvyvs8vEqArGJknmcn_udUgL4tJm4DatmUA/viewformAbstract Talk #1: The initial breakthroughs of deep learning came in the form of predictive tasks such as image classification, where discriminative models were trained with supervised learning algorithms. More recently, there have been exciting developments for generative models trained with unsupervised learning algorithms. Generative models approximate the distribution of the data and open up a wider range of possible applications. Generative Adversarial Networks (GANs) are the most well known of these models; however, they have drawbacks. I will describe an alternative approach called normalizing flows and discuss them in the context of three physics problems: effective field theory measurements at the LHC, lattice quantum chromodynamics, and modeling the density matrix of a quantum system.

Abstract Talk #2: String theory is a theory of quantum gravity that has had strong impacts on theoretical physics and mathematics. In this talk I will describe ways in which deep learning may lead to progress in string theory, with a special focus on broad applications in the string theory landscape. Known properties of the landscape and its relation to computational complexity will be briefly discussed, including ways in which the structure of the theory allows for the avoidance of worst-case complexity; for instance, networks of extra-dimensional spaces connected by topology changing transitions can aid in solving physically relevant Diophantine problems. The talk will focus on two types of problems in string theory. First, generative models will be discussed as a means for approximating statistical predictions, which are crucial given the large landscape of solutions. As a simple application, a conditional Wasserstein DCGAN will be used to learn random matrix approximations to Kahler metrics on Kahler moduli space, which are relevant for the physics of axion-like particles. Second, we will discuss multi-task search problems that arise in the landscape. A reinforcement learning A3C agent will be utilized to solve a multi-task problem in type IIA compactifications on a toroidal orbifold. Significant improvement over a random walker is achieved, a known human strategy is learned by the agent, but an RL-discovered strategy performs about twice as well.

http://pcts.princeton.edu/programs/current/deep-learning-for-physics-seminar-series/121

**Tuesday, November 19, 2019**

Pheno & Vino Seminar

“Signatures of Mirror Stars”

Location: Jadwin Hall, Room 303

Time: 4:00 PM

Speaker(s): Jack Setford, University of Toronto**Description:**Motivated by theories of neutral naturalness, I will argue that Mirror Stars are a generic possibility in any hidden sector with analogues of Standard Model electromagnetism and nuclear physics. I will show that if there exists a tiny kinetic mixing between the dark and SM photon, Mirror Stars capture SM matter from the interstellar medium, which accumulates in the Mirror Star core. This leads to a spectacular and distinctive signature that could be discovered in optical and X-ray searches.

**Wednesday, November 20, 2019**

Physics Group Meeting

“On a Quantum Penrose Inequality”

Location: Bloomberg Hall Physics Library

Time: 1:45 PM

Speaker(s): Adam Levine, Member, School of Natural Sciences, IAS**Description:**Suggested reading:

Marc Mars, Present Status of the Penrose Inequality, arXiv:0906.5566

Netta Engelhardt and Gary Horowitz, A Holographic Argument for the Penrose Inequality in AdS, arXiv:1903.00555

Quantum Penrose Inequality, arXiv:1908.02755

**Wednesday, November 20, 2019**

High Energy Theory Seminar

“Integrable Deformations in Quantum Mechanics, T-Tbar, and SYK”

Location: Jadwin Hall, Room A06

Time: 4:00 PM

Speaker(s): Edgar Shaghoulian, Cornell University**Description:**The Wilsonian paradigm suggests universality of quantum field theory in the infrared. Interestingly, it also suggests universality of quantum mechanics (d=1 quantum field theory) in the*ultraviolet*. This suggests a study of the landscape of the infrared and the robustness of the ultraviolet. I will introduce and solve an infinite class of integrable deformations to quantum mechanics, focusing on a particular deformation inspired by the T-Tbar deformation of two-dimensional quantum field theory. In the context of holography, I will show how these deformations modify Jackiw-Teitelboim gravity in AdS_2. I will also present an equivalent description of the T-Tbar deformation in terms of coupling to worldline gravity. Applications to the Schwarzian theory and SYK will be discussed.

**Thursday, November 21, 2019**

Hamilton Colloquium Series

“The Revolution of Silicon Photonics”

Location: Jadwin Hall, Room A10

Time: 4:00 PM

Speaker(s): Michal Lipson, Columbia University**Description:**We are now experiencing a revolution in optical technologies, where one can print and control massive optical circuits, on a microelectronic chip. This revolution is enabling a whole range of applications that are in need for scalable optical technologies and it is opening the door to areas that only a decade ago were unimaginable.In the past decade, the photonic community witnessed a complete transformation of optics. We went from being able to miniaturize a handful of devices to being able to define and control the flow of light using thousands of monolithically integrated optical components all on a silicon chip. The main drive for silicon photonics is the ability to transmit and manipulate ultra high bandwidth with low power dissipation. Today there are hundreds of products being developed and commercialized towards this goal.

The field of silicon photonics is rapidly evolving and is now enabling completely new applications, ranging from Lidar to biomedical devices. This is partly due to the development of novel chip-scale technologies, novel devices and novel materials compatible with silicon photonics. Many of these technologies and devices can manipulate light across the whole VIS, IR and the Mid IR spectrum. I will discuss these emerging applications, as well as the advancement brought by these novel devices and materials.

The key challenges of the field relate to the scalability of the systems in bandwidth, size and power. Some of these challenges are fundamental and require innovations that break traditional tradeoffs. Novel approaches for switching, modulating and amplifying light have emerged that can open the door to applications that rely on such scalable systems. I will describe the challenges of the field and some of the recent innovations that can potentially address these challenges.

**Monday, November 25, 2019**

Gravity Initiative Lunch

“Stability of Black Holes in Classical GR”

Location: Jadwin Hall, Princeton Gravity Initiative, 4th Floor

Time: 12:30 PM

Speaker(s): Elena Giorgi, Princeton Gravity Initiative, Princeton University**Description:**

**Monday, November 25, 2019**

High Energy Theory Seminar

“TBA”

Location: Bloomberg Lecture Hall

Time: 2:30 PM

Speaker(s): Radu Roiban, Pennsylvania State University**Description:**

**Tuesday, November 26, 2019**

Pheno & Vino Seminar

“TBA”

Location: Jadwin Hall, Room 303

Time: 4:00 PM

Speaker(s): Jo Dunkley, Princeton University

**Wednesday, November 27, 2019**

Physics Group Meeting

“TBA”

Location: Bloomberg Hall Physics Library

Time: 1:45 PM

Speaker(s): TBA, TBA

**Monday, December 2, 2019**

Gravity Initiative Lunch

“TBA”

Location: Jadwin Hall, Princeton Gravity Initiative, 4th Floor

Time: 12:30 PM

Speaker(s): Elias Most, Flatiron Institute**Description:**

**Monday, December 2, 2019**

High Energy Theory Seminar

“TBA”

Location: Bloomberg Lecture Hall

Time: 2:30 PM

Speaker(s): TBA**Description:**

**Tuesday, December 3, 2019**

It from Qubit Conference

“Workshop on Qubits and Spacetime”

Location: Wolfensohn Hall

Time: 6:00 AM

**Description:****Please Note:**This workshop is not open to the general public, but only to active researchers.This workshop will focus on quantum aspects of black holes, focusing on applying ideas from quantum information theory.

This meeting is sponsored by the "It from Qubit"collaboration and is followed by the collaboration meeting in New York City.

https://www.sns.ias.edu/quantum-information-workshop-2019

**Tuesday, December 3, 2019**

Pheno & Vino Seminar

“TBA”

Location: Jadwin Hall, Room 303

Time: 4:00 PM

Speaker(s): Prateek Agrawal, Harvard University

**Wednesday, December 4, 2019**

It from Qubit Conference

“Workshop on Qubits and Spacetime”

Location: Wolfensohn Hall

Time: 6:00 AM

**Description:****Please Note:**This workshop is not open to the general public, but only to active researchers.This workshop will focus on quantum aspects of black holes, focusing on applying ideas from quantum information theory.

This meeting is sponsored by the "It from Qubit"collaboration and is followed by the collaboration meeting in New York City.

https://www.sns.ias.edu/quantum-information-workshop-2019

**Friday, December 6, 2019**

High Energy Theory Seminar

“TBA”

Location: Bloomberg Lecture Hall

Time: 1:45 PM

Speaker(s): Adam Levine, Member, School of Natural Sciences, IAS**Description:**

**Monday, December 9, 2019**

Gravity Initiative Lunch

“TBA”

Location: Jadwin Hall, Princeton Gravity Initiative, 4th Floor

Time: 12:30 PM

Speaker(s): Antonios Tsokaros, University of Illinois**Description:**

**Tuesday, December 10, 2019**

Pheno & Vino Seminar

“TBA”

Location: Jadwin Hall, Room 303

Time: 4:00 PM

Speaker(s): Simona Murgia, University of California, Irvine

**Wednesday, December 11, 2019**

Physics Group Meeting

“TBA”

Location: Bloomberg Hall Physics Library

Time: 1:45 PM

Speaker(s): TBA, TBA

**Thursday, December 12, 2019**

Hamilton Colloquium Series

“TBA”

Location: Jadwin Hall, Room A10

Time: 4:00 PM

Speaker(s): Thierry Mora, Ecole Normale SupĂ©rieure de Paris**Description:**

**Friday, December 13, 2019**

High Energy Theory Seminar

“TBA”

Location: Bloomberg Lecture Hall

Time: 1:45 PM

Speaker(s): Nafiz Ishtiaque, Member, School of Natural Sciences, IAS**Description:**

**Tuesday, February 11, 2020**

Deep Learning for Physics

Location: TBA

Time: 11:45 AM

Speaker(s): TBA

Note: Each talk will be preceded with lunch at 11:45 am. The talks will be held from 12:25-1:30 pm. Please check the specific date for room location.**Description:**

**Wednesday, March 4, 2020**

Gravity Initiative Workshop

“The Future of the PLANCK Data”

Location: Jadwin Hall, PCTS Seminar Room, 4th Floor

Time: 8:00 AM

**Description:**

**Thursday, March 5, 2020**

Gravity Initiative Workshop

“The Future of the PLANCK Data”

Location: Jadwin Hall, PCTS Seminar Room, 4th Floor

Time: 8:00 AM

**Description:**

**Friday, March 6, 2020**

Gravity Initiative Workshop

“The Future of the PLANCK Data”

Location: Jadwin Hall, PCTS Seminar Room, 4th Floor

Time: 8:00 AM

**Description:**

**Tuesday, March 10, 2020**

Deep Learning for Physics

Location: TBA

Time: 11:45 AM

Speaker(s): TBA

Note: Each talk will be preceded with lunch at 11:45 am. The talks will be held from 12:25-1:30 pm. Please check the specific date for room location.**Description:**

**Tuesday, April 7, 2020**

Deep Learning for Physics

Location: TBA

Time: 11:45 AM

Speaker(s): TBA

Note: Each talk will be preceded with lunch at 11:45 am. The talks will be held from 12:25-1:30 pm. Please check the specific date for room location.**Description:**

**Monday, May 4, 2020**

Gravity Initiative Workshop

“Exploring Supermassive Black Holes”

Location: Jadwin Hall, PCTS Seminar Room, 4th Floor

Time: 8:00 AM

**Description:**

**Tuesday, May 5, 2020**

Gravity Initiative Workshop

“Exploring Supermassive Black Holes”

Location: Jadwin Hall, PCTS Seminar Room, 4th Floor

Time: 8:00 AM

**Description:**

**Wednesday, May 6, 2020**

Gravity Initiative Workshop

“Exploring Supermassive Black Holes”

Location: Jadwin Hall, PCTS Seminar Room, 4th Floor

Time: 8:00 AM

**Description:**

**Monday, July 13, 2020**

PiTP 2020

Time: 7:00 AM

**Description:**

**Monday, July 13, 2020**

PiTP 2020

Time: 7:00 AM

**Description:**