LOG#173. Proton decay.

Are diamonds and other (crystalline) jewels/gemstones forever? Well, if protons are stable they are. If not, you are lost! We are all lost indeed in such a case…(However, I am sure that Superman would be fine to know the fact … Continue reading

LOG#170. The shortest papers ever: the list.

Hi, everyone. In this short post I am going to discuss some of the shortest papers ever written all over the world!!!!! This idea came to my mind due to a post by @seanmcarroll on twitter and other social networks… … Continue reading

LOG#134. Chaplygin gas.

Warm Dark Matter candidates: neutrinos, axions, extra relativistic species currently unknown. Cold Dark Matter candidates: many. Pick one (or many!): Z primes, the lightest supersymmetric particle (LSP), gravitino, gaugino, neutralino, ELKO fields, Majorana spinors, the infinite component Majorana field, unparticles, … Continue reading

LOG#107. Basic Cosmology (II).

Evolution of the Universe: the scale factor The Universe expands, and its expansion rate is given by the Hubble parameter (not constant in general!) Remark  (I): The Hubble “parameter” is “constant” at the present value (or a given time/cosmological age), … Continue reading

LOG#106. Basic Cosmology (I).

The next thread is devoted to Cosmology. I will intend to be clear and simple about equations and principles of current Cosmology with a General Relativity background. First of all…I will review the basic concepts of natural units I am … Continue reading

LOG#047. The Askaryan effect.

I discussed and reviewed the important Cherenkov effect and radiation in the previous post, here: http://www.thespectrumofriemannium.com/?p=3276 Today we are going to study a relatively new effect ( new experimentally speaking, because it was first detected when I was an undergraduate … Continue reading