Superstring compactifications with manifest spacetime supersymmetry

• Ano de defesa: 2025
• Autor(a) principal: Daniel, Cassiano Antonio [UNESP]
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: eng
• Instituição de defesa: UNESP
• Palavras-chave em Português: Teoria das supercordas; Supersimetria; Partículas (Física nuclear)
• Link de acesso: https://hdl.handle.net/11449/296591

This thesis explores the superstring compactified to four- and six-dimensional backgrounds. The theory is quantized using the spacetime supersymmetric hybrid formalism for the superstring while leveraging two-dimensional worldsheet methods. After the four-dimensional hybrid description is developed in an electromagnetic background, a superstring field theory action for the first massive states is constructed — both in superspace and in terms of the components fields. The action includes a massive spin-3/2 and a massive spin-2 field propagating in the presence of a constant non-zero U(1) gauge field. Quantization of the superstring compactified to a Calabi-Yau twofold can be achieved using the six-dimensional hybrid description. However, the hybrid formalism allows only half of the eight d = 6 N = 1 SUSYs manifest. We overcome this issue and extend the formalism such that all spacetime SUSYs can be made manifest. The BRST operator, physical states and a scattering amplitude prescription are explicitly constructed. We then study the Type IIB superstring in an Ad'S IND. 3' x 'S POT.3 background. By making use of the Berkovits-Vafa-Witten hybrid formalism for the pure NS-NS flux case, we compute a supersymmetric three-point amplitude of half-BPS vertex operators inserted on the Ad'S IND. 3' boundary. The computation is performed using the PSU(1, 1|2)-covariant variables. It is found that integrating out the fermionic worldsheet fields in the path integral gives rise to the target-space vielbein, which explicitly encodes that the conformal group on the boundary is identified with the symmetry group of the AdS bulk. The superstring in Ad'S IND. 3' x 'S POT.3 can be supported by a mixture of NS-NS and R-R self-dual three-form flux. We construct a manifestly PSU(1, 1|2) × PSU(1, 1|2)- invariant sigma-model action for the superstring in Ad'S IND. 3' x 'S POT.3 x ' T POT.4' with mixed flux. The model is then covariantly quantized and proven to be conformal invariant at the one-loop level. We conclude by showing how one can relate the supersymmetric description with the Berkovits-Vafa-Witten Ad'S IND. 3' x 'S POT.3 worldsheet action with mixed flux.