Tag Info

New answers tagged


The $p$-value statistic is used frequently in physics, most notably in the search for the Higgs boson at the LHC. The $p$-value (which I denote with $\lambda$) is the probability of obtaining such a large $\chi^2$ statistic by chance if the null hypothesis is true, $$ \lambda = p(\chi^2 \ge \chi^2\text{ observed} | H_0) $$ i.e. the area in the right-hand ...


This is a bit of a negative answer, but consider instead an expectation of some other quantity, such as the energy: $$ \langle E \rangle = \sum_i p_i E_i. $$ Now, it's obvious what $E_i$ means - it's the energy of state $i$ - but what does $p_iE_i$ mean? The answer is not very much really - it's the contribution of state $i$ to the expected energy, but it's ...

Top 50 recent answers are included