Emilio Pisanty

In another post, I claimed that there was obviously an oscillating charge in a hydrogen atom when you took the superposition of a 1s and a 2p state. One of the respected members of this community (John Rennie) challenged me on this, saying: Why do you say there is an oscillating charge distribut...

I have recently come across, in several papers, the notion of cross product between two rank-2 tensor, which I find useful for a project I am currently looking into. A useful formulation is given in L. Szabó. A note on cross product between two symmetric second-order tensors. J. Mech. Mater. Str...

The 2023 Nobel Prize in Physics was announced today, and it was awarded to Pierre Agostini, Ferenc Krausz and Anne L’Huillier, for “experimental methods that generate attosecond pulses of light for the study of electron dynamics in matter”. The documents released by the Nobel Foundation along w...

Ultraviolet waves can cause many biological deseases such as cancer or tumor or even make a photosinthesis process be quicker and that can cause also genetic disorders in generations .I found an article speaking of all radiation on stratosphere many nuclear weapons and Mega Tones of dust are in t...

What you have is a MultinormalDistribution. The quadratic and linear forms in the exponential can be rewritten in terms of $-\frac12(\vec{x}-\vec{\mu})^\top\Sigma^{-1}(\vec{x}-\vec{\mu})$ where $\vec{\mu}$ represents the mean and $\Sigma$ the covariance matrix, see the documentation. With this, ...