Category Archives: Nauka (science)

Ogólne zagadnienia ze świata nauki

From SU(1,1) to the Lorentz group

Posted on 2017/04/11 by arkajad

From the two-dimensional disk we are moving to three-dimensional space-time. We will meet Einstein-Poincare-Minkowski special relativity, though in a baby version, with x and y, but without z in space. It is not too bad, because the famous Lorentz transformations, … Continue reading →

Posted in Geometry, Hyperbolic geometry, Mathematica, Special relativity, SU(1,1), Teoria względności szczególna | 3 Comments

Putting a spin on mistakes

Posted on 2017/02/19 by arkajad

I am reading Leopold Infeld, “QUEST: The Evolution of a Scientist“, Readers Union Limited, London 1942. There is a little piece there about errors that drew my attention. The story takes place in Princeton: The next day I met Robertson … Continue reading →

Posted in Nauka (science), Spin and rotations | 2 Comments

Notes on Ehresmann’s connections -Part 2, Frölicher–Nijenhuis bracket

Posted on 2010/12/27 by arkajad

In this note I shall introduce the Frölicher-Nijenhuis bracket – a powerful tool, especially when dealing with connections on fibre bundles. Continue reading →

Posted in Geometry, Nauka (science) | 3 Comments