Comments on Global Symmetries and Anomalies of 5 SCFTs.

We study various aspects of global symmetries in five-dimensional superconformal field theories. Whenever a supersymmetry-preserving relevant deformation is available, the infrared gauge theory description might exhibit a finite order mixed 't Hooft anomaly between a 1-form symmetry and the instantonic symmetry. This anomaly constrains the flavor symmetry group acting faithfully on the SCFT and the consistency of certain RG flows.

Quantization of Axion-Gauge Couplings and Noninvertible Higher Symmetries.

We derive model-independent quantization conditions on the axion couplings (sometimes known as the anomaly coefficients) to the standard model gauge group [SU(3)×SU(2)×U(1)_{Y}]/Z_{q} with q=1, 2, 3, 6. Using these quantization conditions, we prove that any QCD axion model to the right of the E/N=8/3 line on the |g_{aγγ}|-m_{a} plot must necessarily face the axion domain wall problem in a postinflationary scenario. We further demonstrate the higher-group and noninvertible global symmetries in the standard model coupled to a single axion.

Berezin Quantization, Conformal Welding and the Bott-Virasoro Group.

Following Nag-Sullivan, we study the representation of the group of diffeomorphisms of the circle on the Hilbert space of holomorphic functions. Conformal welding provides triangular decompositions for the corresponding symplectic transformations. We apply Berezin formalism and lift this decomposition to operators acting on the Fock space.

Neural network complexity of chaos and turbulence.

Chaos and turbulence are complex physical phenomena, yet a precise definition of the complexity measure that quantifies them is still lacking. In this work, we consider the relative complexity of chaos and turbulence from the perspective of deep neural networks. We analyze a set of classification problems, where the network has to distinguish images of fluid profiles in the turbulent regime from other classes of images such as fluid profiles in the chaotic regime, various constructions of noise and real-world images.

Inference on autoregulation in gene expression with variance-to-mean ratio.

Some genes can promote or repress their own expressions, which is called autoregulation. Although gene regulation is a central topic in biology, autoregulation is much less studied. In general, it is extremely difficult to determine the existence of autoregulation with direct biochemical approaches.

Phases of Wilson Lines in Conformal Field Theories.

We study the low-energy limit of Wilson lines (charged impurities) in conformal gauge theories in 2+1 and 3+1 dimensions. As a function of the representation of the Wilson line, certain defect operators can become marginal, leading to interesting renormalization group flows and for sufficiently large representations to complete or partial screening by charged fields. This result is universal: in large enough representations, Wilson lines are screened by the charged matter fields.

Noninvertible Time-Reversal Symmetry.

In gauge theory, it is commonly stated that time-reversal symmetry only exists at θ=0 or π for a 2π-periodic θ angle. In this Letter, we point out that in both the free Maxwell theory and massive QED, there is a noninvertible time-reversal symmetry at every rational θ angle, i.e.

Using Fano factors to determine certain types of gene autoregulation.

The expression of one gene might be regulated by its corresponding protein, which is called autoregulation. Although gene regulation is a central topic in biology, autoregulation is much less studied. In general, it is extremely difficult to determine the existence of autoregulation with direct biochemical approaches.

Measure for Chaotic Scattering Amplitudes.

We propose a novel measure of chaotic scattering amplitudes. It takes the form of a log-normal distribution function for the ratios r_{n}=δ_{n}/δ_{n+1} of (consecutive) spacings δ_{n} between two (consecutive) peaks of the scattering amplitude. We show that the same measure applies to the quantum mechanical scattering on a leaky torus as well as to the decay of highly excited string states into two tachyons.

Playing With the Index of M-Theory.

Motivated by M-theory, we study rank K-theoretic Donaldson-Thomas theory on a toric threefold . In the presence of compact four-cycles, we discuss how to include the contribution of D4-branes wrapping them. Combining this with a simple assumption on the (in)dependence on Coulomb moduli in the 7d theory, we show that the partition function factorizes and, when is Calabi-Yau and it admits an ADE ruling, it reproduces the 5d master formula for the geometrically engineered theory on ALE space, thus extending the usual geometric engineering dictionary to .

Noninvertible Global Symmetries in the Standard Model.

We identify infinitely many noninvertible generalized global symmetries in QED and QCD for the real world in the massless limit. In QED, while there is no conserved Noether current for the U(1)_{A} axial symmetry because of the Adler-Bell-Jackiw anomaly, for every rational angle 2πp/N, we construct a conserved and gauge-invariant topological symmetry operator. Intuitively, it is a composition of the axial rotation and a fractional quantum Hall state coupled to the electromagnetic U(1) gauge field.

Perfect Fluid Hydrodynamic Picture of Domain Wall Velocities at Strong Coupling.

We show that for a range of strongly coupled theories with a first order phase transition, the domain wall or bubble velocity can be expressed in a simple way in terms of a perfect fluid hydrodynamic formula, and thus in terms of the equation of state. We test the predictions for the domain wall velocities using the gauge/gravity duality.

Black Hole Quasinormal Modes and Seiberg-Witten Theory.

We present new analytic results on black hole perturbation theory. Our results are based on a novel relation to four-dimensional supersymmetric gauge theories. We propose an exact version of Bohr-Sommerfeld quantization conditions on quasinormal mode frequencies in terms of the Nekrasov partition function in a particular phase of the -background.

Kramers-Wannier-like Duality Defects in (3+1)D Gauge Theories.

We introduce a class of noninvertible topological defects in (3+1)D gauge theories whose fusion rules are the higher-dimensional analogs of those of the Kramers-Wannier defect in the (1+1)D critical Ising model. As in the lower-dimensional case, the presence of such noninvertible defects implies self-duality under a particular gauging of their discrete (higher-form) symmetries. Examples of theories with such a defect include SO(3) Yang-Mills (YM) at θ=π, N=1 SO(3) super YM, and N=4 SU(2) super YM at τ=i.

Axial-Current Anomaly in Euler Fluids.

We argue that a close analog of the axial-current anomaly of quantum field theories with fermions occurs in the classical Euler fluid. The conservation of the axial current (closely related to the helicity of inviscid barotropic flow) is anomalously broken by the external electromagnetic field as ∂_{μ}j_{A}^{μ}=2E·B, similar to that of the axial current of a quantum field theory with Dirac fermions, such as QED.

Renormalization Group Flows on Line Defects.

We consider line defects in d-dimensional conformal field theories (CFTs). The ambient CFT places nontrivial constraints on renormalization group (RG) flows on such line defects. We show that the flow on line defects is consequently irreversible and furthermore a canonical decreasing entropy function exists.

Rn emanation measurements for the XENON1T experiment.

The selection of low-radioactive construction materials is of utmost importance for the success of low-energy rare event search experiments. Besides radioactive contaminants in the bulk, the emanation of radioactive radon atoms from material surfaces attains increasing relevance in the effort to further reduce the background of such experiments. In this work, we present the Rn emanation measurements performed for the XENON1T dark matter experiment.

2-Group Symmetries of 6D Little String Theories and T-Duality.

We determine the 2-group structure constants for all the six-dimensional little string theories (LSTs) geometrically engineered in F-theory without frozen singularities. We use this result as a consistency check for T-duality: the 2-groups of a pair of T-dual LSTs have to match. When the T-duality involves a discrete symmetry twist, the 2-group used in the matching is modified.

Homoclinic Renormalization Group Flows, or When Relevant Operators Become Irrelevant.

We study an N=1 supersymmetric quantum field theory with O(M)×O(N) symmetry. Working in 3-ε dimensions, we calculate the beta functions up to second loop order and analyze in detail the renormalization group (RG) flow and its fixed points. We allow N and M to assume general real values, which results in them functioning as bifurcation parameters.

Symmetry Breaking at All Temperatures.

We explore the existence of conformal field theories that persistently break a global symmetry at finite temperature. We identify vector models in (3-ε) spatial dimensions that have internal symmetries broken at any temperature. We study these systems in the small ε regime and in the large rank limit.

Lifetime of Almost Strong Edge-Mode Operators in One-Dimensional, Interacting, Symmetry Protected Topological Phases.

Almost strong edge-mode operators arising at the boundaries of certain interacting one-dimensional symmetry protected topological phases with Z_{2} symmetry have infinite temperature lifetimes that are nonperturbatively long in the integrability breaking terms, making them promising as bits for quantum information processing. We extract the lifetime of these edge-mode operators for small system sizes as well as in the thermodynamic limit. For the latter, a Lanczos scheme is employed to map the operator dynamics to a one-dimensional tight-binding model of a single particle in Krylov space.

Black Holes Often Saturate Entanglement Entropy the Fastest.

There is a simple bound on how fast the entanglement entropy of a subregion of a many-body quantum system can saturate in a quench: t_{sat}≥R/v_{B}, where t_{sat} is the saturation time, R the radius of the largest inscribed sphere, and v_{B} the butterfly velocity characterizing operator growth. By combining analytic and numerical approaches, we show that in systems with a holographic dual, the saturation time is equal to this lower bound for a variety of differently shaped entangling surfaces, implying that the dual black holes saturate the entanglement entropy as fast as possible. This finding adds to the growing list of tasks that black holes are the fastest at.

A trust model for spreading gossip in social networks: a multi-type bootstrap percolation model.

We introduce here a multi-type bootstrap percolation model, which we call ( -BP), and apply it to study information propagation in social networks. In this model, a social network is represented by a graph whose vertices have different labels corresponding to the type of role the person plays in the network (e.g.

Free-Surface Variational Principle for an Incompressible Fluid with Odd Viscosity.

We present variational and Hamiltonian formulations of incompressible fluid dynamics with a free surface and nonvanishing odd viscosity. We show that within the variational principle the odd viscosity contribution corresponds to geometric boundary terms. These boundary terms modify Zakharov's Poisson brackets and lead to a new type of boundary dynamics.