English

Brauer group of moduli stack of parabolic $\textnormal{PSp}(r,\mathbb{C})$--bundles over a curve

Algebraic Geometry 2025-09-12 v1

Abstract

Take an irreducible smooth complex projective curve XX of genus gg, with g3g\,\geq\, 3. Let rr be an even positive integer. We prove that the Brauer group of the moduli stack of stable parabolic PSp(r,C)\textnormal{PSp}(r,\mathbb{C})--bundles on XX, of full-flag parabolic data along a set of marked points on XX, coincides with the Brauer group of the smooth locus of the corresponding coarse moduli space of stable parabolic PSp(r,C)\textnormal{PSp}(r,\mathbb{C})--bundles. Under certain conditions on the parabolic types, we also compute the Brauer group of the smooth locus of this coarse moduli space. Similar computations are also done for the case of partial flags.

Keywords

Cite

@article{arxiv.2509.09378,
  title  = {Brauer group of moduli stack of parabolic $\textnormal{PSp}(r,\mathbb{C})$--bundles over a curve},
  author = {Indranil Biswas and Sujoy Chakraborty and Arijit Dey},
  journal= {arXiv preprint arXiv:2509.09378},
  year   = {2025}
}

Comments

31 pages, comments are welcome