LOG#226. Higgs vs. lambda.

Hi, there. Short post today! The dark energy mystery, a.k.a., the cosmological constant problem or why the observed vacuum energy is to tiny is a big problem with no consensus solution yet. The Standard Model Higgs potential can be written … Continue reading

LOG#224. Vis tenebris.

What is dark energy? Where does it come from? Is it constant? Is it a quantum field? Is it vacuum energy? Nobody knows what is the 70% of the Universe! In the beginning of Physics as Science, Aristotle himself introduced … Continue reading

LOG#217. The 2 pillars.

Time of Cosmic Voyages https://www.youtube.com/watch?v=xEdpSgz8KU4 This is a long post, despite not being a special post (remember I make one of those every 50 posts). What are we going to see here? A five part post! Part(I). A descriptive prelude. … Continue reading

LOG#207. Beck, Zeldovich and maximal acceleration: the vacuum.

Some time ago, Zeldovich derived the following expression for the vacuum energy density: (1)   or equivalently, with a link to Caianiello’s maximal acceleration formula, (2)   Remark: the above vacuum energy density is related to the cosmological constant via … Continue reading

LOG#176. The cosmological integral.

Hi, there! In this short note I am going to introduce you into a big problem from a simple integral I use to call “the cosmological integral” (it should be the cosmological energy density integral, but it is too long…). … Continue reading

LOG#172. Higgscelebration: 3 years of a Higgs-like boson!

In 2012, July 4th…We had the Higgsdependence day! A SM Higgs-like resonance was discovered at the LHC and was announced to the world. Today, we celebrate this discovery of the Higgs-like thing or particle almost 3 years ago. So let … Continue reading

LOG#155. Maximal tension, Λ and quantum gravity.

Hi, folks! Before the upcoming series of thematic blog posts (they are on their way, eager readers), I found a very interesting paper to discuss. The paper is this http://arxiv.org/abs/1408.1820 and the pdf file can be found here http://arxiv.org/pdf/1408.1820v1.pdf . The author of … Continue reading

LOG#142. Basic QFT in curved ST(II).

I. Back to QFT in flat Spacetime. Any scalar quantum field has an action and lagrangian density: in D spacetime dimensions. The lagrangian density is usually written as follows The EOM (equation of motion) reads: A nice feynmanity! Indeed, it … 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