HHIQCD2024

Session

Seminar (5th week)

Nov 11, 2024, 10:00 AM

Panasonic Auditorium, Yukawa Hall (YITP)

Conveners

Seminar (5th week)

• Aleksey Cherman (University of Minnesota)

Seminar (5th week)

• Aleksey Cherman (University of Minnesota)

Seminar (5th week)

• Hidenori Fukaya (Osaka Univ.)

Seminar (5th week)

• Hidenori Fukaya (Osaka Univ.)

Seminar (5th week)

• David Kaplan (University of Washington)

Seminar (5th week)

• David Kaplan (University of Washington)

Seminar (5th week)

• Tin Sulejmanpasic (Durham University)

Seminar (5th week)

• Tin Sulejmanpasic (Durham University)

Seminar (5th week)

• Theo Jacobson (University of California, Los Angeles)

Seminar (5th week)

• Theo Jacobson (University of California, Los Angeles)

Seminar (5th week)

• Torsten Zache (Innsbruck University & IQOQI)

Seminar (5th week)

• Torsten Zache (Innsbruck University & IQOQI)

Seminar (5th week)

• Xiaojun Yao (University of Washington)

Seminar (5th week)

• Xiaojun Yao (University of Washington)

Seminar (5th week)

• Arata Yamamoto (University of Tokyo)

Seminar (5th week)

• Sinya Aoki (Kyoto University - YITP)

116. Chiral gauge theory on the lattice

Prof. David Kaplan (University of Washington)

11/11/24, 10:00 AM

5th week (Formal developments and other frontiers in lattice QCD)

A fermion representation with exact chiral symmetry can be obtained on a 5-dimensional lattice with a single boundary, circumventing the Nielsen-Ninomiya theorem. I discuss this as well as a proposal for gauging the theory, and objections that have been raised.

112. Lattice Weyl Fermion on a single spherical domain-wall 1

Shoto Aoki (The University of Tokyo)

11/11/24, 11:30 AM

5th week (Formal developments and other frontiers in lattice QCD)

In the standard lattice domain-wall fermion formulation, two flat domain-walls are put where both of the left- and right-handed massless modes appear on the walls. In this work we investigate a single spherical domain-wall fermion mass term embedded into a flat square three-dimensional lattice. In the free fermion case, we find that a single Weyl fermion appears at the wall and it feels...

97. Lattice Weyl Fermion on a single spherical domain-wall 2

Naoto Kan (Osaka University)

11/11/24, 12:00 PM

5th week (Formal developments and other frontiers in lattice QCD)

We discuss a single domain-wall system with a nontrivial curved background by considering a massive fermion on a 3D square lattice, where the domain-wall is a 2D sphere. In the presence of a topologically nontrivial U(1) link gauge field, we observe the emergence of a zero mode with opposite chirality localized at the center where the gauge field is singular. This results in the low-energy...

85. Persistent order and beyond-BKT phase transitions

Aleksey Cherman (University of Minnesota)

11/11/24, 2:00 PM

5th week (Formal developments and other frontiers in lattice QCD)

I'll discuss a Monte Carlo and analytic exploration of some simple lattice models that feature persistent order, namely that they are in an ordered phase at all temperatures. These models have BKT-like phase transitions that separate regions with spontaneous symmetry breaking and CFT phases. Understanding how to study such systems using Monte Carlo methods is a first step toward the study of...

42. Novel Lattice Formulation of 2D Chiral Gauge Theory via Bosonization

Soma Onoda (Kyushu University)

11/11/24, 3:00 PM

5th week (Formal developments and other frontiers in lattice QCD)

Recently, lattice formulations of Abelian chiral gauge theory in two dimensions have been
devised on the basis of the Abelian bosonization. A salient feature of these 2D lattice for-
mulations is that the gauge invariance is exactly preserved for anomaly-free theories and thus
is completely free from the question of the gauge mode decoupling. In the present paper, we
propose a yet another...

108. D-Theory: Asymptotically Free Quantum Fields from the Dimensional Reduction of Discrete Variables

Uwe-Jens Wiese (Bern University)

11/11/24, 4:00 PM

3rd week (Nishinomiya-Yukawa symposium)

CP(N-1) models in (1+1)-d have a global SU(N) symmetry and share many features with QCD. They are asyptotically free, have a non-perturbatively generated mass gap, and non-trivial theta-vacuum states. CP(N-1) models can be regularized unconventionally by using discrete SU(N) quantum spins forming a (2+1)-d spin ladder that consists of n transversely coupled quantum spin chains. The (1+1)-d...

61. Phases of matter in systems with a discrete 1-form symmetry and the role of monopoles and center vortices

Tin Sulejmanpasic (Durham University)

11/12/24, 10:00 AM

5th week (Formal developments and other frontiers in lattice QCD)

I will discuss theories with the $Z_N$ 1-form symmetry and argue that theories in 4d generically have three phases: the spontaneously broken phase, the restored (confined) phase and the coulomb phase. Natural string-like objects appear in this analysis, which we associate with the center vortices of the corresponding $SU(N)$ gauge theory. In addition the discussion also reveals particle-like...

101. Bridging two semiclassical confinement mechanisms: monopole and center vortex

Yui Hayashi (YITP, Kyoto University)

11/12/24, 11:30 AM

5th week (Formal developments and other frontiers in lattice QCD)

The two promising scenarios for quark confinement are monopole and center-vortex mechanisms. These mechanisms are realized in the weakly coupled semiclassical frameworks: monopole semiclassics on ${\mathbb{R}}^3\times S^1$ and center-vortex semiclassics on ${\mathbb{R}}^2\times T^2$. In this presentation, we will bridge two semiclassical descriptions, illustrating how the BPS and KK monopoles...

109. Gauging C on the Lattice

Theo Jacobson (University of California, Los Angeles)

11/12/24, 2:00 PM

5th week (Formal developments and other frontiers in lattice QCD)

We will discuss general aspects of charge conjugation symmetry in Euclidean lattice field theories including its dynamical gauging. As an application, we construct O(2) gauge theory on the lattice using a non-abelian generalization of the Villain formulation. This lattice discretization preserves a myriad of generalized global symmetries of the continuum theory, and we describe how to...

55. Instanton Density Operator in Lattice QCD from Higher Category Theory

Jing-Yuan Chen (Institute for Advanced Study Tsinghua University)

11/12/24, 3:30 PM

5th week (Formal developments and other frontiers in lattice QCD)

A long standing problem in lattice QCD is to naturally define the Yang-Mills instanton on the lattice. I will show how this problem is, and has to be, resolved by higher category theory.

To resolve the problem, the notion of lattice Yang-Mills must be refined at a conceptual level, in a way similar to how Villainization refines XY model and $U(1)$ lattice gauge theory. The remarkable...

34. The theta angle dependence of the metastable vacuum energy in 2d $\mathbb{C}{P}^{N-1}$ model

Takahiro Yokokura (Tohoku University)

11/12/24, 4:30 PM

5th week (Formal developments and other frontiers in lattice QCD)

In this talk, I will discuss metastable vacua of 2d $\mathbb{C}{P}^{N-1}$ model in the large $N$ limit.In particular we will focus on the theta angle dependence of the metastable vacuum energy.We will see the vacua become unstable at large theta angles due to high decay rates.This work is in collaboration with Tsubasa Sugeno and Kazuya Yonekura.

114. Quantum simulation of string-breaking in SU(2)k lattice gauge theory

Torsten Zache (Innsbruck University & IQOQI)

11/13/24, 10:00 AM

5th week (Formal developments and other frontiers in lattice QCD)

Simulating dynamical properties of non-abelian gauge theories is considered to be an ideal target for quantum computers.
In this talk, I will present recent progress toward simulating a confining flux string and its breaking due to creation of dynamical charges in a minimal setup. Our proposal is based on a q-deformed formulation of SU(2) lattice gauge theory, truncating the gauge group to...

122. Towards quantum simulating QCD: loop string hadron approach

Indrakshi Raychowdhury (BITS Pilani, K K Birla Goa Campus)

11/13/24, 11:30 AM

5th week (Formal developments and other frontiers in lattice QCD)

Full-fledged Quantum computation/simulation of lattice QCD is a long-term goal and requires developing a set of strategies starting from foundational level. This includes a convenient Hamiltonian framework for the theory along with the Hilbert space construction compatible with the principle of gauge invariance. The recently developed Loop-string-hadron approach is a promising framework for...

26. Quantum Simulations of the Schwinger Model: from vacuum to dense matter

Marc Illa (University of Washington)

11/13/24, 2:00 PM

5th week (Formal developments and other frontiers in lattice QCD)

Quantum electrodynamics in 1+1 dimensions (the Schwinger model) exhibits a number of features similar to quantum chromodynamics in 3+1D, including confinement and a fermion condensate, making it the perfect sandbox during the NISQ era. In this talk, I will present new scalable algorithms that use the symmetries and hierarchy of length scales in the Schwinger model (and generally applicable to...

77. Computing mass spectra of gauge theories in the Hamiltonian formalism

Akira Matsumoto (Yukawa Institute for Theoretical Physics, Kyoto University)

11/13/24, 3:30 PM

5th week (Formal developments and other frontiers in lattice QCD)

We present a couple of methods to compute the mass spectra of composite particles (hadrons) in gauge theories,
which can be implemented in quantum computing or tensor networks in the Hamiltonian formalism.
The hadron mass can be efficiently computed from the one-point function, combining the correlation function to deal with the operator mixing.
Alternatively, we can obtain the dispersion...

71. QED in two spatial dimensions: study confinement with quantum computing

Enrico Rinaldi (Quantinuum)

11/13/24, 4:30 PM

5th week (Formal developments and other frontiers in lattice QCD)

Current noisy quantum computers can be already used to investigate properties of quantum systems. Here we focus on lattice QED in (2+1)D including fermionic matter.
This complex quantum field theory with dynamical gauge and matter fields has similarities with QCD, in particular asymptotic freedom and confinement.
We define a suitable setup to measure the static potential between two static...

69. Fermion determinants on a quantum computer

Judah Unmuth-Yockey (Fermilab)

11/15/24, 10:00 AM

5th week (Formal developments and other frontiers in lattice QCD)

I discuss a quantum algorithm to compute the logarithm of the determinant of the staggered fermion matrix, assuming access to a classical lattice gauge field configuration. The algorithm uses the quantum eigenvalue transform, and quantum mean estimation, giving a query complexity that scales like O(V log(V)) in the matrix dimension V.

18. Z3 lattice gauge theory as a toy model of QCD

Arata Yamamoto (University of Tokyo)

11/15/24, 11:30 AM

5th week (Formal developments and other frontiers in lattice QCD)

The infinite-dimensional Hilbert space of SU(3) gauge field makes the quantum simulation of QCD difficult. In this talk, I would like to propose Z3 lattice gauge theory as a toy model with the finite-dimensional Hilbert space. I will discuss the similarity and difference compared with QCD and the application to quantum simulation.

74. Non Abelian Lattice Gauge Theories: From Quantum Simulation to Ergodicity

Pietro Silvi (University of Padua)

11/15/24, 2:00 PM

5th week (Formal developments and other frontiers in lattice QCD)

Non-abelian gauge theories play a pivotal role in our description of the universe, from low to high-energies, but their complexity hinders our understanding of their emergent phenomena. In this talk, we will consider a one-dimensional SU(2) lattice gauge theory with dynamical matter, the simplest theory supporting the existence of baryons and mesons. We will show how to build a quantum...

95. Quantum Many-Body Scars in 2+1D Gauge Theories

Joao Pinto Barros (ETH Zurich)

11/15/24, 3:30 PM

5th week (Formal developments and other frontiers in lattice QCD)

Real-time dynamics of Quantum Chromodynamics and other strongly coupled gauge theories present significant challenges for standard Monte Carlo methods due to severe sign problems. This limitation makes these problems ideal candidates for quantum simulation techniques. Identifying phenomena that can be tackled using near-term quantum simulators is crucial for understanding real-time dynamics in...

86. Formulation of SU(N) Lattice Gauge Theories with Schwinger Fermions

Hanqing Liu (Los Alamos National Laboratory)

11/15/24, 4:30 PM

5th week (Formal developments and other frontiers in lattice QCD)

The recent advancements towards scalable fault-tolerant quantum computing have brought excitement about simulating lattice gauge theories on quantum computers. However, digital quantum computers require truncating the infinite-dimensional link Hilbert space to finite dimensions. In this talk, we focus on the $\mathrm{SU}(N)$ gauge theory coupled to $N_f$ flavor of quarks and propose a...