arXiv subjects

Masato Okado

Publications and source records attributed to Masato Okado.

At least 37 records · Page 2Linked to original sources

arXiv2016

Stochastic $R$ matrix for $U_q(A^{(1)}_n)$

We show that the quantum $R$ matrix for symmetric tensor representations of $U_q(A^{(1)}_n)$ satisfies the sum rule required for its stochastic interpretation under a suitable gauge. Its matrix elements at a special point of the spectral parameter are found to factorize into the form that naturally extends Povolotsky's local transition rate in the $q$-Hahn process for $n=1$. Based on these results we formulate new discrete and continuous time integrable Markov processes on a one-dimensional chain in terms of $n$ species of particles obeying asymmetric stochastic dynamics. Bethe ansatz eigenvalues of the Markov matrices are also given.

math.QA↗

arXiv2016

Tetrahedron equation and generalized quantum groups

We construct $2^n$-families of solutions of the Yang-Baxter equation from $n$-products of three-dimensional $R$ and $L$ operators satisfying the tetrahedron equation. They are identified with the quantum $R$ matrices for the Hopf algebras known as generalized quantum groups. Depending on the number of $R$'s and $L$'s involved in the product, the trace construction interpolates the symmetric tensor representations of $U_q(A^{(1)}_{n-1})$ and the anti-symmetric tensor representations of $U_{-q^{-1}}(A^{(1)}_{n-1})$, whereas a boundary vector construction interpolates the $q$-oscillator representation of $U_q(D^{(2)}_{n+1})$ and the spin representation of $U_{-q^{-1}}(D^{(2)}_{n+1})$. The intermediate cases are associated with an affinization of quantum super algebras.

math.QA↗

arXiv2016

Type $D_n^{(1)}$ rigged configuration bijection

We establish a bijection between the set of rigged configurations and the set of tensor products of Kirillov--Reshetikhin crystals of type $D^{(1)}_n$ in full generality. We prove the invariance of rigged configurations under the action of the combinatorial $R$-matrix on tensor products and show that the bijection preserves certain statistics (cocharge and energy). As a result, we establish the fermionic formula for type $D_n^{(1)}$. In addition, we establish that the bijection is a classical crystal isomorphism.

math.QA↗

arXiv2016

Inhomogeneous generalization of multispecies totally asymmetric zero range process

The $n$-species totally asymmetric zero range process ($n$-TAZRP) on one-dimensional periodic chain studied recently by the authors is a continuous time Markov process where arbitrary number of particles can occupy the same sites and hop to the adjacent sites only in one direction with a priority constraint according to their species. In this paper we introduce an $n$-parameter generalization of the $n$-TAZRP having inhomogeneous transition rate. The steady state probability is obtained in a matrix product form and also by an algorithm related to combinatorial $R$.

math-ph↗

arXiv2015

Multispecies TASEP and the tetrahedron equation

We introduce a family of layer to layer transfer matrices in a three-dimensional (3D) lattice model which can be viewed as partition functions of the $q$-oscillator valued six-vertex model on $m \times n$ square lattice. By invoking the tetrahedron equation we establish their commutativity and bilinear relations mixing various boundary conditions. At $q=0$ and $m=n$, they ultimately yield a new proof of the steady state formula for the $n$-species totally asymmetric simple exclusion process (TASEP) obtained recently by the authors, revealing the 3D integrability in the matrix product construction.

nlin.SI↗

arXiv2015

Multispecies TASEP and combinatorial $R$

We identify the algorithm for constructing steady states of the $n$-species totally asymmetric simple exclusion process (TASEP) on $L$ site periodic chain by Ferrari and Martin with a composition of combinatorial $R$ for the quantum affine algebra $U_q(\widehat{sl}_L)$ in crystal base theory. Based on this connection and the factorized form of the $R$ matrix derived recently from the tetrahedron equation, we establish a new matrix product formula for the steady state of the TASEP which is expressed in terms of corner transfer matrices of the $q$-oscillator valued five-vertex model at $q=0$.

math-ph↗

arXiv2015

Similarity and Kirillov-Schilling-Shimozono bijection

The behavior of the Kirillov-Schilling-Shimozono bijection is examined under the similarity map on Kirillov-Reshetikhin crystals. It enables us to define this bijection over $\mathbb{Q}$. Conjectures on the extension to $\mathbb{R}$ is also presented.

math.QA↗

arXiv2015

Tetrahedron Equation and Quantum $R$ Matrices for modular double of $U_q(D^{(2)}_{n+1}), U_q(A^{(2)}_{2n})$ and $U_q(C^{(1)}_{n})$

We introduce a homomorphism from the quantum affine algebras $U_q(D^{(2)}_{n+1}), U_q(A^{(2)}_{2n}), U_q(C^{(1)}_{n})$ to the $n$-fold tensor product of the $q$-oscillator algebra ${\mathcal A}_q$. Their action commute with the solutions of the Yang-Baxter equation obtained by reducing the solutions of the tetrahedron equation associated with the modular and the Fock representations of ${\mathcal A}_q$. In the former case, the commutativity is enhanced to the modular double of these quantum affine algebras.

math-ph↗

arXiv2014

Tetrahedron equation and quantum $R$ matrices for $q$-oscillator representations

We review and supplement the recent result by the authors on the reduction of the three dimensional $R$ (3d $R$) satisfying the tetrahedron equation to the quantum $R$ matrices for the $q$-oscillator representations of $U_q(D^{(2)}_{n+1})$, $U_q(A^{(2)}_{2n})$ and $U_q(C^{(1)}_{n})$. A new formula for the 3d $R$ and a quantum $R$ matrix for $n=1$ are presented and a proof of the irreducibility of the tensor product of the $q$-oscillator representations is detailed.

math-ph↗

arXiv2014

Tetrahedron equation and quantum R matrices for $q$-oscillator representations of $U_q(A^{(2)}_{2n}), U_q(C^{(1)}_{n})$ and $U_q(D^{(2)}_{n+1})$

The intertwiner of the quantized coordinate ring $A_q(sl_3)$ is known to yield a solution to the tetrahedron equation. By evaluating their $n$-fold composition with special boundary vectors we generate series of solutions to the Yang-Baxter equation. Finding their origin in conventional quantum group theory is a clue to the link between two and three dimensional integrable systems. We identify them with the quantum $R$ matrices associated with the $q$-oscillator representations of $U_q(A^{(2)}_{2n})$, $U_q(C^{(1)}_n)$ and $U_q(D^{(2)}_{n+1})$.

math-ph↗

arXiv2014

Virtual crystals and Kleber's algorithm

Kirillov and Reshetikhin conjectured what is now known as the fermionic formula for the decomposition of tensor products of certain finite dimensional modules over quantum affine algebras. This formula can also be extended to the case of $q$-deformations of tensor product multiplicities as recently conjectured by Hatayama et al. (math.QA/9812022 and math.QA/0102113). In its original formulation it is difficult to compute the fermionic formula efficiently. Kleber (q-alg/9611032 and math.QA/9809087) found an algorithm for the simply-laced algebras which overcomes this problem. We present a method which reduces all other cases to the simply-laced case using embeddings of affine algebras. This is the fermionic analogue of the virtual crystal construction by the authors, which is the realization of crystal graphs for arbitrary quantum affine algebras in terms of those of simply-laced type.

math.QA↗

arXiv2013

Tetrahedron equation and quantum R matrices for infinite dimensional modules of U_q(A^{(1)}_1) and U_q(A^{(2)}_2)

From the q-oscillator solution to the tetrahedron equation associated with a quantized coordinate ring, we construct solutions to the Yang-Baxter equation by applying a reduction procedure formulated earlier by S. Sergeev and the first author. The results are identified with the quantum R matrices for the infinite dimensional modules of U_q(A^{(1)}_1) and U_q(A^{(2)}_2) corresponding to an affinization of Verma modules of their subalgebras isomorphic to U_q(sl_2) and U_{q^4}(sl_2).

math-ph↗

arXiv2013

A Common Structure in PBW Bases of the Nilpotent Subalgebra of $U_q(\mathfrak{g})$ and Quantized Algebra of Functions

For a finite-dimensional simple Lie algebra $\mathfrak{g}$, let $U^+_q(\mathfrak{g})$ be the positive part of the quantized universal enveloping algebra, and $A_q(\mathfrak{g})$ be the quantized algebra of functions. We show that the transition matrix of the PBW bases of $U^+_q(\mathfrak{g})$ coincides with the intertwiner between the irreducible $A_q(\mathfrak{g})$-modules labeled by two different reduced expressions of the longest element of the Weyl group of $\mathfrak{g}$. This generalizes the earlier result by Sergeev on $A_2$ related to the tetrahedron equation and endows a new representation theoretical interpretation with the recent solution to the 3D reflection equation for $C_2$. Our proof is based on a realization of $U^+_q(\mathfrak{g})$ in a quotient ring of $A_q(\mathfrak{g})$.

math.QA↗

arXiv2012

Simplicity and similarity of Kirillov-Reshetikhin crystals

We show that the Kirillov-Reshetikhin crystal B^{r,s} for nonexceptional affine types is simple and have the similarity property. As a corollary of the first fact we can derive that the tensor product of KR crystals is connected. Variations of the second property are also given.

math.RT↗

arXiv2012

A solution of the 3D reflection equation from quantized algebra of functions of type B

Let A_q(g) be the quantized algebra of functions associated with simple Lie algebra g defined by generators obeying the so called RTT relations. We describe the embedding $A_q(B_2) \hookrightarrow A_q(C_2)$ explicitly. As an application, a new solution of the Isaev-Kulish 3D reflection equation is constructed by combining the embedding with the previous solution for A_q(C_2) by the authors.

math-ph↗

arXiv2012

Affine crystal structure on rigged configurations of type D_n^(1)

Extending the work arXiv:math/0508107, we introduce the affine crystal action on rigged configurations which is isomorphic to the Kirillov-Reshetikhin crystal B^{r,s} of type D_n^(1) for any r,s. We also introduce a representation of B^{r,s} (r not equal to n-1,n) in terms of tableaux of rectangular shape r x s, which we coin Kirillov-Reshetikhin tableaux (using a non-trivial analogue of the type A column splitting procedure) to construct a bijection between elements of a tensor product of Kirillov-Reshetikhin crystals and rigged configurations.

math.QA↗

arXiv2011

Stable Rigged Configurations for Quantum Affine Algebras of Nonexceptional Types

For an affine algebra of nonexceptional type in the large rank we show the fermionic formula depends only on the attachment of the node 0 of the Dynkin diagram to the rest, and the fermionic formula of not type A can be expressed as a sum of that of type A with Littlewood-Richardson coefficients. Combining this result with math.CO/9901037 and arXiv:1002.3715 we settle the X=M conjecture under the large rank hypothesis.

math.QA↗

arXiv2011

Soliton cellular automaton associated with $G_2^{(1)}$ crystal base

We calculate the combinatorial $R$ matrix for all elements of $\mathcal{B}_l\otimes \mathcal{B}_1$ where $\mathcal{B}_l$ denotes the $G_2^{(1)}$-perfect crystal of level $l$, and then study the soliton cellular automaton constructed from it. The solitons of length $l$ are identified with elements of the $A_1^{(1)}$-crystal $\tilde{\mathcal{B}}_{3l}$. The scattering rule for our soliton cellular automaton is identified with the combinatorial $R$ matrix for $A_1^{(1)}$-crystals.

math.QA↗