The question of the origin of mass is one of the more important issues in theoretical physics. The existence (or not) of extra dimensions of space and time will likely affect to the final solution of this unsolved problem. The … Continue reading

# Category Archives: QFT

An interesting but relatively unknown variation of the Bohr model is to use a logarithmic potential energy. In that case, we have (1) (2) (3) Bohr quantization rules impose and that so (4) and then (5) (6) (7) The momentum … Continue reading

The Bohr model of the hydrogen atom is a cool and nice “toy model”. It serves as a prototype in many applications, even if it is not fully “quantum”. It does provide many applications. In this post, and the followings, … Continue reading

The year 2013 is coming to its end…And I have a final gift for you. An impossible post! This year was the Bohr model 100th anniversary. I have talked about this subject already, here, here and here. The hydrogen spectrum is very important in Astronomy, … Continue reading

Final round of this thread! Approximate methods We will evaluate the path integral (PI) using an approximation known as “saddle point”. It is a semiclassical approximation sometimes referred as the method of steepest descent. Moreover, it is based on the … Continue reading

Round 3! Fight… with path integrals! XD Introduction: generic aspects Consider a particle moving in one dimension (the extension to ND is trivial), the hamiltonian being of the usual form: The fundamental question and problem in the path integral (PI) … Continue reading

Are you gaussian? Are you normal? My second post about the path integral will cover functional calculus, and some basic definitions, properties and formulae. What is a functional? It is a gadget that produces a number! Numbers are cool! Functions … Continue reading

My next thematic thread will cover the Feynman path integral approach to Quantum Mechanics! The standard formulation of Quantum Mechanics is well known. It was built and created by Schrödinger, Heisenberg and Dirac, plus many others, between 1925-1931. Later, it … Continue reading

Idea: Black Holes (BH) are “not” truly black. BH emit thermal radiation at the Hawking temperature and it is proportional to the surface gravity () of the BH. Mathematically, we have as the Bekenstein-Hawking temperature. In the case of a … Continue reading

What is the Unruh effect? Description: any accelerated observer in the traditional Minkovski state OBSERVE a thermal spectrum of particles. When we refer to the accelerated observer, usually it is called the Rindler observer in the literature as well. In … Continue reading