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Creators/Authors contains: "Volpato, Roberto"

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  1. ; ; ; (, Annales Henri Poincaré)
    Abstract We discuss a set of heterotic and type II string theory compactifications to$$1+1$$ 1 + 1 dimensions that are characterized by factorized internal worldsheet CFTs of the form$$V_1\otimes \bar{V}_2$$ V 1 ⊗ V ¯ 2 , where$$V_1, V_2$$ V 1 , V 2 are self-dual (super) vertex operator algebras. In the cases with spacetime supersymmetry, we show that the BPS states form a module for a Borcherds–Kac–Moody (BKM) (super)algebra, and we prove that for each model the BKM (super)algebra is a symmetry of genus zero BPS string amplitudes. We compute the supersymmetric indices of these models using both Hamiltonian and path integral formalisms. The path integrals are manifestly automorphic forms closely related to the Borcherds–Weyl–Kac denominator. Along the way, we comment on various subtleties inherent to these low-dimensional string compactifications. 
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  2. ; ; ; (, Journal of High Energy Physics)
    null (Ed.)
    A bstract We study some special features of F 24 , the holomorphic c = 12 superconformal field theory (SCFT) given by 24 chiral free fermions. We construct eight different Lie superalgebras of “physical” states of a chiral superstring compactified on F 24 , and we prove that they all have the structure of Borcherds-Kac-Moody superalgebras. This produces a family of new examples of such superalgebras. The models depend on the choice of an $$ \mathcal{N} $$ N = 1 supercurrent on F 24 , with the admissible choices labeled by the semisimple Lie algebras of dimension 24. We also discuss how F 24 , with any such choice of supercurrent, can be obtained via orbifolding from another distinguished c = 12 holomorphic SCFT, the $$ \mathcal{N} $$ N = 1 supersymmetric version of the chiral CFT based on the E 8 lattice. 
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  3. ; ; (, Journal of Physics A: Mathematical and Theoretical)
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  4. ; ; ; ; (, Journal of High Energy Physics)
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