Mattia Biancotto | Searcharxiv

arXiv2026

The Runkel-Watts string

We introduce and solve a new family of two-dimensional string theories obtained by coupling Liouville CFT to the generalized Runkel-Watts CFT. By taking an appropriate limit of the complex Liouville string, we derive an all-genus formula for its string amplitudes, and formulate a duality with a matrix integral. We explain that it can be interpreted as 2d SU(2) Yang-Mills theory coupled to gravity. We show that it also directly relates to other minimal string constructions such as the A-series minimal string.

hep-th↗

arXiv2026

Degenerations of flat connections on Riemann surfaces

The integration kernels for polylogarithm functions on a compact Riemann surface of arbitrary genus $h$ are shown to close as the surface undergoes a non-separating degeneration to one of genus $h{-}1$. Explicit formulas are obtained for the non-separating degeneration of the multivariable Enriquez connection for genus $h$ with an arbitrary number of variables to the Enriquez connection for genus $h{-}1$ with two additional punctures whose Lie algebra generators are related to the original ones by the characteristic Bernoulli generating functions known from the degeneration at $h=1$. Analogous degeneration formulas are obtained for the single-valued DHS kernels at the leading order in the real degeneration parameter that is adapted to relating modular tensors at genus $h$ and $h{-}1$.

hep-th↗