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  2. Lanczos approximation - Wikipedia

    en.wikipedia.org/wiki/Lanczos_approximation

    Thus computing the gamma function becomes a matter of evaluating only a small number of elementary functions and multiplying by stored constants. The Lanczos approximation was popularized by Numerical Recipes , according to which computing the gamma function becomes "not much more difficult than other built-in functions that we take for granted ...

  3. Gradient descent - Wikipedia

    en.wikipedia.org/wiki/Gradient_descent

    Illustration of gradient descent on a series of level sets. Gradient descent is based on the observation that if the multi-variable function is defined and differentiable in a neighborhood of a point , then () decreases fastest if one goes from in the direction of the negative gradient of at , ().

  4. Decay scheme - Wikipedia

    en.wikipedia.org/wiki/Decay_scheme

    The decay scheme of a radioactive substance is a graphical presentation of all the transitions occurring in a decay, and of their relationships. Examples are shown below. It is useful to think of the decay scheme as placed in a coordinate system, where the vertical axis is energy, increasing from bottom to top, and the horizontal axis is the proton number, increasing from left to right.

  5. Branching fraction - Wikipedia

    en.wikipedia.org/wiki/Branching_fraction

    In particle physics and nuclear physics, the branching fraction (or branching ratio) for a decay is the fraction of particles that decay by an individual decay mode or with respect to the total number of particles which decay. It applies to either the radioactive decay of atoms or the decay of elementary particles. [1]

  6. Bateman equation - Wikipedia

    en.wikipedia.org/wiki/Bateman_equation

    In nuclear physics, the Bateman equation is a mathematical model describing abundances and activities in a decay chain as a function of time, based on the decay rates and initial abundances. The model was formulated by Ernest Rutherford in 1905 [1] and the analytical solution was provided by Harry Bateman in 1910. [2]

  7. Multipolarity of gamma radiation - Wikipedia

    en.wikipedia.org/wiki/Multipolarity_of_gamma...

    Transitions between excited states (or excited states and the ground state) of a nuclide lead to the emission of gamma quanta. These can be classified by their multipolarity. [1] There are two kinds: electric and magnetic multipole radiation. Each of these, being electromagnetic radiation, consists of an electric and a magnetic field.

  8. Radioactive decay - Wikipedia

    en.wikipedia.org/wiki/Radioactive_decay

    Radioactive decay (also known as nuclear decay, radioactivity, radioactive disintegration, or nuclear disintegration) is the process by which an unstable atomic nucleus loses energy by radiation. A material containing unstable nuclei is considered radioactive. Three of the most common types of decay are alpha, beta, and gamma decay.

  9. Exponential decay - Wikipedia

    en.wikipedia.org/wiki/Exponential_decay

    A quantity undergoing exponential decay. Larger decay constants make the quantity vanish much more rapidly. This plot shows decay for decay constant (λ) of 25, 5, 1, 1/5, and 1/25 for x from 0 to 5. A quantity is subject to exponential decay if it decreases at a rate proportional to its current value.