Scalar Fields and the Dark Sector: A String Theory Perspective

Scalar fields are a ubiquitous feature of string theory compactifications, typically appearing in axion–saxion pairs with non-trivial interactions. Motivated by this structure, I will discuss how such scalars can play a dynamical role in the dark sector of the universe. First, I will present a model in which one scalar behaves as dark matter and the other as dark energy, providing a unified picture of the dark sector. I will then turn to multifield quintessence models, where accelerated expansion can arise even with steep potentials, thereby evading recent quantum gravity swampland constraints and offering a possible framework for the evolving dark energy hinted at by observations. Time permitting, I will also touch on coupled dark sector models that can effectively mimic a phantom equation of state.

https://unam.zoom.us/j/84371291925?pwd=mMHwgWGPXLVvDPzGCaz3XR18mbaqDY.1

Meeting ID: 843 7129 1925
Passcode:   AEnergi4$