We use cookies to distinguish you from other users and to provide you with a better experience on our websites. Close this message to accept cookies or find out how to manage your cookie settings.
To save content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about saving content to .
To save content items to your Kindle, first ensure [email protected]
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about saving to your Kindle.
Note you can select to save to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
We study the spaces of twisted conformal blocks attached to a $\Gamma$-curve $\Sigma$ with marked $\Gamma$-orbits and an action of $\Gamma$ on a simple Lie algebra $\mathfrak {g}$, where $\Gamma$ is a finite group. We prove that if $\Gamma$ stabilizes a Borel subalgebra of $\mathfrak {g}$, then the propagation theorem and factorization theorem hold. We endow a flat projective connection on the sheaf of twisted conformal blocks attached to a smooth family of pointed $\Gamma$-curves; in particular, it is locally free. We also prove that the sheaf of twisted conformal blocks on the stable compactification of Hurwitz stack is locally free. Let $\mathscr {G}$ be the parahoric Bruhat–Tits group scheme on the quotient curve $\Sigma /\Gamma$ obtained via the $\Gamma$-invariance of Weil restriction associated to $\Sigma$ and the simply connected simple algebraic group $G$ with Lie algebra $\mathfrak {g}$. We prove that the space of twisted conformal blocks can be identified with the space of generalized theta functions on the moduli stack of quasi-parabolic $\mathscr {G}$-torsors on $\Sigma /\Gamma$ when the level $c$ is divisible by $|\Gamma |$ (establishing a conjecture due to Pappas and Rapoport).
The basic Factorization Theorem is proved here, which explicitly relates the space of vacua on an s-pointed curve of genus g with a single node with that of the space of vacua on the normalization (which is of genus g-1) marked with s+2 points. We sheafify the construction of the space of vacua for a family of s-pointed curves and show that it is a coherent sheaf. We further show that this sheaf for a smooth family is locally free and admits a functorial flat projective connection. This connection generalizes the Knizhnik--Zamolodchikov connection for the projective line. Using this, we show that the dimension of the space of vacua does not depend either upon the choice of the holomorphic structure on the curve or on the choice of the marked points on the curve. Using the Factorization Theorem, we prove an inductive formula to calculate the dimension of the space of vacua on a genus-g curve in terms of a genus-(g-1) curve though with s+2 points. Using this successively, we are reduced to calculate the dimension of vacua on a projective line with s+2g points. Using a similar decomposition, the problem further reduces to that for three marked points on the projective line.
Recommend this
Email your librarian or administrator to recommend adding this to your organisation's collection.