Speaker
Prof.
Nihan Katirci
(Doğuş U.)
Description
In this talk, we present a higher-dimensional framework in which the curvature of compact internal space can drive an effective sign change in the 4D cosmological constant, mimicking the behavior required by phenomenological extensions of ÎCDM. A spontaneous transition in the size of the extra dimensions leads to a mirror AdS-dS shift in the external spacetime, offering a novel geometric origin for late-time acceleration. This mechanism also predicts an evolving gravitational coupling and may offer new insight into existing cosmological tensions. Model-independent implications for the dynamics and observables will be discussed at the end of the talk.