The following equations are satisfied:\begin{align}\sum_{j} \delta_{ij} a_j = a_i,\\\sum_{i} a_i\delta_{ij} = a_j,\\\sum_{k} \delta_{ik}\delta_{kj} = \delta_{ij}.\end{align}Therefore, δij can be cons ...
The graph of the delta function is usually thought of as following the whole x-axis and the positive y-axis. Despite its name, the delta function is not truly a function, at least not a usual one with ...
Main article: gamma-ray astronomyA few gamma rays in astronomy are known to arise from gamma decay (see discussion of SN1987A) but most do not.Gamma radiation, like X-radiation, can be produced by a v ...
The first gamma ray source to be discovered historically was the radioactive decay process called gamma decay. In this type of decay, an excited nucleus emits a gamma ray almost immediately upon forma ...
The constant first appeared in a 1734 paper by the Swiss mathematician Leonhard Euler, titled De Progressionibus harmonicis observationes (Enestr?m Index 43). Euler used the notations C and O for the ...
Statistical interpretation From the statistical point of view, β is a numerical quantity relating two macroscopic systems in equilibrium. The exact formulation is as follows. Consider two systems, 1 ...
An unstable atomic nucleus with an excess of neutrons may undergo β? decay, where a neutron is converted into a proton, an electron and an electron-type antineutrino (the antiparticle of the neutrin ...
The angular acceleration can be defined as either:{\alpha} = \frac{{d\omega}}{dt} = \frac{d^2{\theta}}{dt^2} , or{\alpha} = \frac{a_T}{r} ,where {\omega} is the angular velocity, a_T is the linear tan ...
Four equivalent definitions of α in terms of other fundamental physical constants are:\alpha = \frac{k_\mathrm{e} e^2}{\hbar c} = \frac{1}{(4 \pi \varepsilon_0)} \frac{e^2}{\hbar c} = \frac{e^2 c \mu ...
years 1899 and 1900, physicists Ernest Rutherford (working in McGill University in Montreal, Canada) and Paul Villard (working in Paris) separated radiation into three types: eventually named alpha, b ...
Main article: Alpha decayThe most well-known source of alpha particles is alpha decay of heavier ( 106 u atomic weight) atoms. When an atom emits an alpha particle in alpha decay, the atom's mass numb ...
The ohm is defined as a resistance between two points of a conductor when a constant potential difference of 1.0 volt, applied to these points, produces in the conductor a current of 1.0 ampere, the c ...
The definition of a halting probability relies on the existence of prefix-free universal computable functions. Such a function, intuitively, represents a programming language with the property that no ...
A (topological) surface is a topological space in which every point has an open neighbourhood homeomorphic to some open subset of the Euclidean plane E2. Such a neighborhood, together with the corresp ...
