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Minoru Wakimoto

Publications and source records attributed to Minoru Wakimoto.

At least 19 recordsLinked to original sources

On modular invariance of quantum affine $W$-algebras

We find modular transformations of normalized characters for the following $W$-algebras: (a) $W^{min}_k(\frak{g})$, where $\frak{g}=D_n \, (n \geq 4)$, or $E_6$, $E_7$, $E_8$, and $k$ is a negative integer $\geq -2$, or $\geq -\frac{h^{\vee}}{6}-1$, respectively; (b) quantum Hamiltonian reduction of the $\hat{\frak{g}}$-module $L(kΛ_0)$, where $\frak{g}$ is a simple Lie algebra, $f$ is its non-zero nilpotent element, and $k$ is a principal admissible level with the denominator $u > θ(x)$, where $2x$ is the Dynkin characteristic of $f$ and $θ$ is the highest root of $\frak{g}$. We prove that these vertex algebras are modular invariant. A conformal vertex algebra is called modular invariant if its character $tr_V q^{L_0-c/24}$ converges to a holomorphic modular function in the complex upper half-plane on a congruence subgroup. We find explicit formulas for their characters. Modular invariance of $V$ is important since, in particular, conjecturally it implies that $V$ is simple, and that $V$ is rational, provided that it is lisse.

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On the characters of a certain series of N=4 superconformal modules II

In this paper we compute the characters of certain non-irreducible N=4 superconformal modules which are different from the ones treated in our previous paper, and study their relation with characters of N=2 superconformal modules. Also, for these non-irreducible N=4 modules, we deduce the expression of characters in terms of string functions.

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On the characters of a certain series of N=4 superconformal modules

In this paper we study the N=4 superconformal modules obtained from the quantum Hamiltonian reduction of principal admissible representations of the affine Lie superalgebra $\hat{A}(1,1)$, and show that there exists a series of N=4 superconformal modules whose characters are modular functions and written explicitly by the Mumford's theta functions.

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Mock theta functions and indefinite modular forms

In the explicit formula for the signed mock theta functions $Φ^{(-)[m,s]}$ obtained from the coroot lattice of $D(2,1;a)$, functions with indefinite quadratic forms naturally take place. We compute their modular transformation properties by applying the Zwegers' modification theory of mock theta functions and show that the $\mathbf{C}$-linear span of these functions is $SL_2(\mathbf{Z})$-invariant.

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Mock theta functions and characters of N=3 superconformal modules IV

In this paper we obtain explicit formulas for mock theta functions $Φ^{[m,s]}(τ, z_1, z_2,t)$ $(m \in \frac12 \mathbf{N}, s \in \frac12 \mathbf{Z})$ by using the coroot lattice of the Lie superalgebra $D(2,1,a)$ and the Kac-Peterson's identity. As its application, we study the branching functions of tensor products of N=3 modules and prove the formula conjectured in the previous paper.

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Mock theta functions and indefinite modular forms II

In this paper, we compute the Zwegers's modification of the mock theta functions $Φ^{[m,0] \, \ast}$ and study the modular transformation properties of the indefinite modular forms which appear in the explicit formula for the modified functions $\tildeΦ^{[m,0] \, \ast}$.

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Mock theta functions and characters of N=3 superconformal modules II

We obtain an explicit formula for the mock theta function $Φ^{[m,s]}$ in the case when either $m$ or $s$ is a half of an odd integer by using the coroot lattice of $D(2,1;a)$. This enables us, together with the recurrence formula for $Φ^{[m,s]}$, to know $Φ^{[m,s]}$ for all $m$ and $s$. As its application, we deduce explicit formulas for the character and the supercharacter of N=3 modules obtained from the quantum Hamiltonian reduction of $\hat{osp}(3|2)$-modules.

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Local and non-local multiplicative Poisson vertex algebras and differential-difference equations

We develop the notions of multiplicative Lie conformal and Poisson vertex algebras, local and non-local, and their connections to the theory of integrable differential-difference Hamiltonian equations. We establish relations of these notions to $q$-deformed $W$-algebras and lattice Poisson algebras. We introduce the notion of Adler type pseudodifference operators and apply them to integrability of differential-difference Hamiltonian equations.

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Poisson $λ$-brackets for differential-difference equations

We introduce the notion of a multiplicative Poisson $λ$-bracket, which plays the same role in the theory of Hamiltonian differential-difference equations as the usual Poisson $λ$-bracket plays in the theory of Hamiltonian PDE. We classify multiplicative Poisson $λ$-brackets in one difference variable up to order 5. Applying the Lenard-Magri scheme to a compatible pair of multiplicative Poisson $λ$-brackets of order 1 and 2, we establish integrability of some differential-difference equations, generalizing the Volterra chain.

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