Tag: gravity

The howling Universe
Before I moved from IFT to IPhT, I filmed a video all about what standard sirens are and why they’re useful for cosmology. The video is now on Youtube, in English with Spanish subtitles. Take a look!

The distance duality relation
The distance duality relation tells us how, assuming that photons propagate on null geodesics in a pseudoRiemannian spacetime and that their number is conserved, luminosity and angular diameter distances are related, via where dL is the luminosity distance, dA the angular diameter distance and z the redshift. This relation was introduced by Etherington in 1933,…

Thesis offcuts: the ancient history of general relativity
I have recently been thinking a lot about what introductory and background material I want to include in my PhD thesis, as my selfimposed December deadline continues to hurtle towards me at an alarming speed. Concurrent with this thinking, I’ve also recently been enjoying a fantastic book called The Poincaré Conjecture by Donal O’Shea, all…