Astrophysics Seminar

The laws of nature ought to be independent of the units of measurement." The premise sounds sensible enough as it agrees with our intuitions and experiences; however, in the context of relativistic theories of gravity, this simple notion leads to various counter-intuitive and interesting phenomena. The standard model of late-time cosmology is built upon the framework of the general theory of relativity. A conformal transformation, equivalent to spacetime-dependent re-scaling of units, can provide alternative but equivalent descriptions of Einstein's gravity through a wide class of modified theories of gravity. Although the 'physics' remains the same in these different conformal representations, the evolution of the universe may look drastically different depending on the conformal frame. In this talk, we will explore a few interesting consequences arising from the conformal representations. We will try to make sense of "cosmological redshift in a static universe!" We will also see how such a duality hints at the possibility of non-trivial quantum features in a large expanding universe.