A new track, “Funky Matters”. An excursion into particle physics #nerdmetal

“Funky Matters” (a play with words) is a song/essay about the discoveries as well as the uncertainties of Particle Physics. Funk and jazz structures and rhythms develop on a metal arrangement, with clean singing and choruses to sing along with (lyrics below).
#nerdmetal

Quantum Prana: Vocals, guitar, bass; lyrics, production
Second Order Effects: Keyboards
Klas Granqvist: Drums
Special thanks to Elisa Mucciarelli and Tatu Hiltunen.

———————————————————————————
FUNKY MATTERS
Ancient Greeks figurin’ it all,
Democritos, the atoms, reduction to the call
Fundamental particles, grains of cosmology
Dividing life, by analogy, with our reality

Galilei’s method of induction
(Was) grounded on eye observation
Solitons / got noted / while ridin’ a horse
Newton and Huygens were fighting
Over new tools for understanding
How funky matters / make up the world
Aether was then invented
For light propagation
However the experiments, couldn’t confirm the equation

Einstein eventually, found the solution
Special relativity killed the funky matter
And gave us / Star Trek

Will string theory save us all?
Will we see the curvaton?
Quantum gravity for all!

—————–
CHORUS
Funky matters to all
Come on and join us / at / the / shopping mall
Warping space and time
Enter the quantum loop, and join the ride
—————-

We’re all cool funky matters
Dancing on warping dimensions
We all live under a Calabi-Yau
Supergravity takes the ball
Superpartner of the graviton
Radiative corrections
Are looping in the action
A new bunch of particles was then invented
But nobody has seen them in the Universe
Dark matter remains very dark
Though supersymmetry protects the Higgs

We all need a superpartner!
Will we see the dilaton?
Quantum gravity for all!
—————–
CHORUS 2
Funky matters to all
Come join us / at / the / shopping mall
We’re all cool funky matters
Hunting and searching / the grand unification
—————–
CHORUS 3
We’re all cool funky matters
Particle or wave, (it) doesn’t really matter
Warping space and time
Quantum gravity for all!

Theoretical physics paper now published

My article on reheating and gravitino production in MSSM inflation is now published in The European Physical Journal C. It is a full access publication, if you are interested you can find it here:

https://link.springer.com/article/10.1140/epjc/s10052-017-5269-8

Abstract

In the framework of MSSM inflation, matter and gravitino production are here investigated through the decay of the fields which are coupled to the udd inflaton, a gauge-invariant combination of squarks. After the end of inflation, the flat direction oscillates about the minimum of its potential, losing at each oscillation about 56% of its energy into bursts of gauge/gaugino and scalar quanta when crossing the origin. These particles then acquire a large inflaton VEV-induced mass and decay perturbatively into the MSSM quanta and gravitinos, transferring the inflaton energy very efficiently via instant preheating. Regarding thermalization, we show that the MSSM degrees of freedom thermalize very quickly, yet not immediately by virtue of the large vacuum expectation value of the inflaton, which breaks the SU(3)C×U(1)YSU(3)C×U(1)Y symmetry into a residual U(1). The energy transfer to the MSSM quanta is very efficient, since full thermalization is achieved after only O(40)O(40) complete oscillations. The udd inflaton thus provides an extremely efficient reheating of the Universe, with a temperature Treh=O(108GeV)Treh=O(108GeV), which allows for instance several mechanisms of baryogenesis. We also compute the gravitino number density from the perturbative decay of the flat direction and of the SUSY multiplet. We find that the gravitinos are produced in negligible amount and satisfy cosmological bounds such as the Big Bang nucleosynthesis (BBN) and dark matter (DM) constraints.

My new cosmology paper is out!

My latest paper in cosmology is now public! It took many years to write, as it was a single author side-project on a subject that is very different from my main field. My PhD was indeed in particle cosmology, while now I am mostly working on building physics and methods for energy saving in buildings. I am however still relatively active in theoretical physics, and this is meant to be the first article of a comeback into the field.

https://arxiv.org/abs/1702.01051

Here is the abstract:

//

In the framework of MSSM inflation, matter and gravitino production are here investigated through the decay of the fields which are coupled to the udd inflaton, a gauge invariant combination of squarks. After the end of inflation, the flat direction oscillates about the minimum of its potential, losing at each oscillation about 56\% of its energy into bursts of gauge/gaugino and scalar quanta when crossing the origin. These particles then acquire a large inflaton VEV-induced mass and decay perturbatively into the MSSM quanta and gravitinos, transferring the inflaton energy very efficiently via instant preheating.
Regarding thermalization, we show that the MSSM degrees of freedom thermalize very quickly, yet not immediately by virtue of the large vacuum expectation value of the inflaton, which breaks the SU(3)C×U(1)Y symmetry into a residual U(1). Compared to the case of LLe-type inflaton previously studied, we find an even more efficient energy transfer to the MSSM quanta, due to the enhanced particle content of the supersymmetric (SUSY) multiplet that is coupled to the flat direction. Full thermalization is achieved indeed after only O(40) oscillations.
We also compute the gravitino number density from the perturbative decay of the flat direction and of the SUSY multiplet. In agreement with the literature, the inflaton produces a negligible amount of gravitinos and does not raise any cosmological issues. On the contrary, the fields to which it is coupled are responsible for a severe gravitino overproduction problem, which is caused by their large VEV-induced effective masses. We argue that possible solutions might include non-coherent oscillations of multiple flat directions or fragmentation of the inflaton condensate with formation of Q-balls.

//