Open-string integrals with multiple unintegrated punctures at genus one

Mar 17, 2022
83 pages
Published in:
  • JHEP 10 (2022) 159
  • Published: Oct 25, 2022
e-Print:
Report number:
  • UUITP-14/22

Citations per year

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Abstract: (Springer)
We study integrals appearing in intermediate steps of one-loop open-string amplitudes, with multiple unintegrated punctures on the A-cycle of a torus. We construct a vector of such integrals which closes after taking a total differential with respect to the N unintegrated punctures and the modular parameter τ. These integrals are found to satisfy the elliptic Knizhnik-Zamolodchikov-Bernard (KZB) equations, and can be written as a power series in α′ — the string length squared- in terms of elliptic multiple polylogarithms (eMPLs). In the N-puncture case, the KZB equation reveals a representation of B1,N_{1,N}, the braid group of N strands on a torus, acting on its solutions. We write the simplest of these braid group elements — the braiding one puncture around another — and obtain generating functions of analytic continuations of eMPLs. The KZB equations in the so-called universal case is written in terms of the genus-one Drinfeld-Kohno algebra t1,N \mathfrak{t} _{1,N}d \mathfrak{d} , a graded algebra. Our construction determines matrix representations of various dimensions for several generators of this algebra which respect its grading up to commuting terms.
Note:
  • 44+39 pages and ancillary file
  • Differential and Algebraic Geometry
  • Scattering Amplitudes
  • string: scattering amplitude
  • tree approximation
  • string: open
  • torus
  • modular
  • braid group