Now, let’s finish the proof of the Hopf-Rinow theorem (the first one) started yesterday. We need to show that given a Riemannian manifold which is a metric space , the existence of arbitrary geo… more →
Delta Epsilonswrote 1 month ago: Reference: Moore, Thomas A., A General Relativity Workbook, University Science Books (2013) – … more →
wrote 1 month ago: Reference: Moore, Thomas A., A General Relativity Workbook, University Science Books (2013) – … more →
wrote 1 month ago: Reference: Moore, Thomas A., A General Relativity Workbook, University Science Books (2013) – … more →
wrote 2 months ago: The definition of a metric space guarantees that if we pick three points from it, we can draw a tria … more →
wrote 5 months ago: Up to a constant factor, there is just one conformally invariant Riemannian metric on the disk . Ind … more →
wrote 9 months ago: In the last post I talked about the physics and considerations behind the gravity train. A crucial p … more →
wrote 10 months ago: The gravitational field is constructed as a physical field in the spirit of Faraday and Maxwell, and … more →
wrote 1 year ago: The real destiny of the machine [is] to merge itself with natural organisms. - Jack Burnham, B … more →
wrote 1 year ago: Growing up I used to think a lot about time travel. It was both a mental escape and a complete fasci … more →
wrote 1 year ago: In Architecture or Techno-utopia: Politics After Modernism, Felicity Scott maps the migration of mi … more →
wrote 1 year ago: Este perfect logic, si, pe deasupra, potrivit ultimelor descoperiri si speculatii astrofizice, chia … more →
wrote 1 year ago: With the introduction of “Buckyballs” and “Fullerenes” into the scientific lexicon in 1985, Fuller’s … more →
wrote 2 years ago: … more →
wrote 2 years ago: Here is a (prompt!) reply from Mark Girolami corresponding to the earlier post: In preparation for t … more →
wrote 3 years ago: I am now aiming to prove an important fixed point theorem: Theorem 1 (Elie Cartan) Let be a c … more →
wrote 3 years ago: I’m going to keep the same notation as before. In particular, we’re studying how the en … more →
wrote 3 years ago: Now, let’s finish the proof of the Hopf-Rinow theorem (the first one) started yesterday. We ne … more →
wrote 3 years ago: Ok, yesterday I covered the basic fact that given a Riemannian manifold , the geodesics on (with res … more →
wrote 3 years ago: Fix a Riemannian manifold with metric and Levi-Civita connection . Then we can talk about geodesics … more →