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A categorification of representations of $U_q(\mathfrak{gl}_{1|1})$

Alexei Oblomkov, Lev Rozansky

TL;DR

This work constructs a geometric categorification of the action of $U_q(\mathfrak{gl}_{1|1})$ on $(\mathbb{C}^{1|1})^{\otimes N}$ via Fourier–Mukai functors between derived categories $\mathcal{D}(\lambda)$ of Calabi–Yau total spaces $Y(\lambda)$ over Grassmannians. It proves that the categorified generators $\mathcal{E}(\lambda)$ and $\mathcal{F}(\lambda)$ satisfy the corresponding nilpotent and cone relations, and that decategorification in localized $\mathbb{C}^*$-equivariant $K$-theory recovers the expected $2^N$-dimensional representation $(\mathbb{C}^{1|1})^{\otimes N}$. The approach hinges on precise FM kernel constructions using determinants of tautological bundles, generalized Koszul complexes, and push-forwards, yielding a coherent algebro-geometric realization of the quantum group action. The authors sketch a path to generalize to $U_q(\mathfrak{gl}_{m|n})$ via flag varieties, Slodowy slices, and related geometric structures, linking to prior work on categorifications and suggesting broader applicability to symmetric powers and other representations.

Abstract

We categorify the action of $U_q(\mathfrak{gl}_{1|1})$ on the tensor product of its vector representations $(\mathbb{C}^{1|1})^{\otimes N}$. The generators $E$ and $F$ are represented by Fourier-Mukai functors between the derived categories of coherent sheaves on the total spaces of "semi-parabolic" vector bundles over the Grassmannians $Gr(k,N)$.

A categorification of representations of $U_q(\mathfrak{gl}_{1|1})$

TL;DR

This work constructs a geometric categorification of the action of on via Fourier–Mukai functors between derived categories of Calabi–Yau total spaces over Grassmannians. It proves that the categorified generators and satisfy the corresponding nilpotent and cone relations, and that decategorification in localized -equivariant -theory recovers the expected -dimensional representation . The approach hinges on precise FM kernel constructions using determinants of tautological bundles, generalized Koszul complexes, and push-forwards, yielding a coherent algebro-geometric realization of the quantum group action. The authors sketch a path to generalize to via flag varieties, Slodowy slices, and related geometric structures, linking to prior work on categorifications and suggesting broader applicability to symmetric powers and other representations.

Abstract

We categorify the action of on the tensor product of its vector representations . The generators and are represented by Fourier-Mukai functors between the derived categories of coherent sheaves on the total spaces of "semi-parabolic" vector bundles over the Grassmannians .
Paper Structure (12 sections, 4 theorems, 75 equations)

This paper contains 12 sections, 4 theorems, 75 equations.

Key Result

Theorem 1

Thus defined, the sheaves $\mathcal{E}(\lambda)$ and $\mathcal{F}(\lambda)$ satisfy the following relations: where $\alpha$ and $\beta$ are the appropriate morphisms between the corrresponding sheaves to be specified in the proof.

Theorems & Definitions (6)

  • Theorem 1
  • Corollary 1
  • Remark 1
  • Proposition 1
  • proof
  • Corollary 2