Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

arXiv:1802.09164 · Journal of Physics A Mathematical and Theoretical

Matrix product solutions to the reflection equation from three dimensional integrability

Atsuo Kuniba, Vincent Pasquier

Published May 10, 2018• 9 citations
arXivHTMLPDF

Abstract

Abstract We formulate a quantized reflection equation in which q -boson valued L and K matrices satisfy the reflection equation up to conjugation by a solution to the Isaev–Kulish 3D reflection equation. By forming its n -concatenation along the q -boson Fock space followed by suitable reductions, we construct families of solutions to the reflection equation in a matrix product form connected to the 3D integrability. They involve the quantum R matrices of the antisymmetric tensor representations of and the spin representations of , and .

DOI
10.1088/1751-8121/aac3b4

Related papers

Reflection K matrices associated with an Onsager coideal of U p ( A n − 1 ( 1 ) ) , U p ( B n ( 1 ) ) , U p ( D n ( 1 ) ) and U p ( D n + 1 ( 2 ) )

Atsuo Kuniba, Masato Okado, Akihito Yoneyama

Abstract We determine the intertwiners of a family of Onsager coideal subalgebras of the quantum affine algebra in the fundamental representations and in the spin representations. They reproduce the reflection K matrices obtained recently by the matrix product construction connected to the three dimensional integrability. In particular the present approach provides the first proof of the reflection equation for the non type A cases.

arXiv:1904.05653•Journal of Physics A Mathematical and Theoretical•Jul 30, 2019•4 citations

Quantum spin chains from Onsager algebras and reflection K-matrices

Atsuo Kuniba, Vincent Pasquier

We present a representation of the generalized p-Onsager algebras Op(An−1(1)), Op(Dn+1(2)), Op(Bn(1)), Op(B˜n(1)) and Op(Dn(1)) in which the generators are expressed as local Hamiltonians of XXZ type spin chains with various boundary terms reflecting the Dynkin diagrams. Their symmetry is described by the reflection K matrices which are obtained recently by a q-boson matrix product construction related to the 3D integrability and characterized by Onsager coideals of quantum affine algebras. The spectral decomposition of the K matrices with respect to the classical part of the Onsager algebra is described conjecturally. We also include a proof of a certain invariance property of boundary vectors in the q-boson Fock space playing a key role in the matrix product construction.

arXiv:1907.07881•Nuclear Physics B•Oct 8, 2019•7 citations

Dynamical boundary conditions for integrable lattices.

A. V. Tsiganov

Some special solutions to the reflection equation are considered. These boundary matrices are defined on the common quantum space with the other operators in the chain. The relations with the Drinfeld twist are discussed. PACS: 02.90.+p, 03.20.+i,03.65.Fd, 11.30.-j 0 1 On a covariance property of the reflection equation Let the operator-valued function R(u) : C → Aut(V ⊗ V) be a solution to the quantum Yang-Baxter equation [1] in a finite-dimensional linear space V. Let us connect with a given matrix R(u) two associative algebras TR and UR generated by noncommutative entries of the square matrices T(u) and K(u) satisfying the fundamental commutator relation [1, 2] or the reflection equation [3, 4] R12(u − v) 1

•Jan 1, 1998•11 citations

Triangular solutions to the reflection equation for U q ( s l n ^ )

Dmitry Kolyaskin, Vladimir V. Mangazeev

Abstract We study solutions of the reflection equation related to the quantum affine algebra U q ( s l n ^ ) . First, we explain how to construct a family of stochastic integrable vertex models with fixed boundary conditions. Then, we construct upper- and lower-triangular solutions of the reflection equation related to symmetric tensor representations of U q ( s l n ^ ) with arbitrary spin. We also prove the star–star relation for the Boltzmann weights of the Ising-type model, conjectured by Bazhanov and Sergeev, and use it to verify certain properties of the solutions obtained.

arXiv:2402.05442•Journal of Physics A Mathematical and Theoretical•May 17, 2024•0 citations

Integrable Matrix Product States from boundary integrability

Balázs Pozsgay, Lorenzo Piroli, Eric Vernier

We consider integrable Matrix Product States (MPS) in integrable spin chains and show that they correspond to “operator valued” solutions of the so-called twisted Boundary Yang-Baxter (or reflection) equation. We argue that the integrability condition is equivalent to a new linear intertwiner relation, which we call the “square root relation”, because it involves half of the steps of the reflection equation. It is then shown that the square root relation leads to the full Boundary Yang-Baxter equations. We provide explicit solutions in a number of cases characterized by special symmetries. These correspond to the “symmetric pairs” (SU(N),SO(N)) and (SO(N),SO(D) \otimes ⊗ SO(N-D)), where in each pair the first and second elements are the symmetry groups of the spin chain and the integrable state, respectively. These solutions can be considered as explicit representations of the corresponding twisted Yangians, that are new in a number of cases. Examples include certain concrete MPS relevant for the computation of one-point functions in defect AdS/CFT.

arXiv:1812.11094•SciPost Physics•May 27, 2019•49 citations

Integrable Matrix Product States from boundary integrability

Balázs Pozsgay, Piroli, L., Vernier, E.

We consider integrable Matrix Product States (MPS) in integrable spin chains and show that they correspond to "operator valued" solutions of the so-called twisted Boundary Yang-Baxter (or reflection) equation. We argue that the integrability condition is equivalent to a new linear intertwiner relation, which we call the "square root relation", because it involves half of the steps of the reflection equation. It is then shown that the square root relation leads to the full Boundary Yang-Baxter equations. We provide explicit solutions in a number of cases characterized by special symmetries. These correspond to the "symmetric pairs" $(SU(N),SO(N))$ and $(SO(N),SO(D)\otimes SO(N-D))$, where in each pair the first and second elements are the symmetry groups of the spin chain and the integrable state, respectively. These solutions can be considered as explicit representations of the corresponding twisted Yangians, that are new in a number of cases. Examples include certain concrete MPS relevant for the computation of one-point functions in defect AdS/CFT.

•May 27, 2019•50 citations
Abstract We formulate a quantized reflection equation in which q -boson valued L and K matrices satisfy the reflection equation up to conjugation by a solution to the Isaev–Kulish 3D reflection equation. By forming its n -concatenation along the q -boson Fock space followed by suitable reductions, we construct families of solutions to the reflection equation in a matrix product form connected to the 3D integrability. They involve the quantum R matrices of the antisymmetric tensor representations of and the spin representations of , and .
We present a representation of the generalized p-Onsager algebras Op(An−1(1)), Op(Dn+1(2)), Op(Bn(1)), Op(B˜n(1)) and Op(Dn(1)) in which the generators are expressed as local Hamiltonians of XXZ type spin chains with various boundary terms reflecting the Dynkin diagrams. Their symmetry is described by the reflection K matrices which are obtained recently by a q-boson matrix product construction related to the 3D integrability and characterized by Onsager coideals of quantum affine algebras. The spectral decomposition of the K matrices with respect to the classical part of the Onsager algebra is described conjecturally. We also include a proof of a certain invariance property of boundary vectors in the q-boson Fock space playing a key role in the matrix product construction.
Some special solutions to the reflection equation are considered. These boundary matrices are defined on the common quantum space with the other operators in the chain. The relations with the Drinfeld twist are discussed. PACS: 02.90.+p, 03.20.+i,03.65.Fd, 11.30.-j 0 1 On a covariance property of the reflection equation Let the operator-valued function R(u) : C → Aut(V ⊗ V) be a solution to the quantum Yang-Baxter equation [1] in a finite-dimensional linear space V. Let us connect with a given matrix R(u) two associative algebras TR and UR generated by noncommutative entries of the square matrices T(u) and K(u) satisfying the fundamental commutator relation [1, 2] or the reflection equation [3, 4] R12(u − v) 1
Abstract We study solutions of the reflection equation related to the quantum affine algebra U q ( s l n ^ ) . First, we explain how to construct a family of stochastic integrable vertex models with fixed boundary conditions. Then, we construct upper- and lower-triangular solutions of the reflection equation related to symmetric tensor representations of U q ( s l n ^ ) with arbitrary spin. We also prove the star–star relation for the Boltzmann weights of the Ising-type model, conjectured by Bazhanov and Sergeev, and use it to verify certain properties of the solutions obtained.
We consider integrable Matrix Product States (MPS) in integrable spin chains and show that they correspond to “operator valued” solutions of the so-called twisted Boundary Yang-Baxter (or reflection) equation. We argue that the integrability condition is equivalent to a new linear intertwiner relation, which we call the “square root relation”, because it involves half of the steps of the reflection equation. It is then shown that the square root relation leads to the full Boundary Yang-Baxter equations. We provide explicit solutions in a number of cases characterized by special symmetries. These correspond to the “symmetric pairs” (SU(N),SO(N)) and (SO(N),SO(D) \otimes ⊗ SO(N-D)), where in each pair the first and second elements are the symmetry groups of the spin chain and the integrable state, respectively. These solutions can be considered as explicit representations of the corresponding twisted Yangians, that are new in a number of cases. Examples include certain concrete MPS relevant for the computation of one-point functions in defect AdS/CFT.
We consider integrable Matrix Product States (MPS) in integrable spin chains and show that they correspond to "operator valued" solutions of the so-called twisted Boundary Yang-Baxter (or reflection) equation. We argue that the integrability condition is equivalent to a new linear intertwiner relation, which we call the "square root relation", because it involves half of the steps of the reflection equation. It is then shown that the square root relation leads to the full Boundary Yang-Baxter equations. We provide explicit solutions in a number of cases characterized by special symmetries. These correspond to the "symmetric pairs" (SU(N),SO(N))(SU(N),SO(N))(SU(N),SO(N)) and (SO(N),SO(D)⊗SO(N−D))(SO(N),SO(D)\otimes SO(N-D))(SO(N),SO(D)⊗SO(N−D)), where in each pair the first and second elements are the symmetry groups of the spin chain and the integrable state, respectively. These solutions can be considered as explicit representations of the corresponding twisted Yangians, that are new in a number of cases. Examples include certain concrete MPS relevant for the computation of one-point functions in defect AdS/CFT.