A bstract The scale at which quantum gravity becomes manifest, the species scale Λ s, has
recently been argued to take values parametrically lower than the Planck scale. We use …

We propose a new topological vertex formalism for a type IIB (p, q) 5-brane web with an O5-
plane. We apply our proposal to five-dimensional N= 1 Sp (1) gauge theory with N f= 0, 1, 8 …

We study the resurgent structure of Walcher's real topological string on general Calabi--Yau
manifolds. We find all-orders trans-series solutions to the corresponding holomorphic …

This thesis, written as a compendium of articles, investigates some broad consequences of
allowing for the dynamical change of spacetime topology in string theory, in the context of …

The scale at which quantum gravity becomes manifest, the species scale $\Lambda_s $, has
recently been argued to take values parametrically lower than the Planck scale. We use …

We consider the real topological string on certain noncompact toric Calabi-Yau three-folds
X, in its physical realization describing an orientifold of type IIA on X with an O4-plane and a …

A bstract We discuss the physical superstring correlation functions in type I theory (or
equivalently type II with orientifold) that compute real topological string amplitudes. We …

The Thesis comprises work done at SISSA (Trieste) and UAM (Madrid) under supervision of
A. Uranga during academic years 2013-2016 and published in the following works. In the …