Holography, dualities and D-branes

Abstract

This thesis is based on the gravity/gauge duality and consists of four different parts. The first part is devoted to the construction of backreacted geometries corresponding to the near brane limit of the D3-D5 brane intersection. The geometries corresponding to the addition of massless and massive flavors and the solution dual to a field theory at non-zero temperature are constructed. The second part focuses on the computation of the spectrum of fluctuations of the Gaiotto-Maldacena geometries. The third part is centered on the addition of brane defects to the Brandhuber-Oz geometry. The fourth part covers the analysis of the integrability of strings in a class of geometries in Massive type IIA supergravity found by Cremonesi and Tomasiello.