gammas

Gammas is the plural form of gamma and is used in various fields to denote different concepts that share the same symbol. The most familiar reference is to gamma rays, but the term also denotes mathematical functions and physical quantities arising in different contexts.

Gamma rays are high‑energy photons with energies typically above 100 keV. They are produced in radioactive decay, nuclear reactions, and many astrophysical processes. Gamma rays are highly penetrating and ionizing, so shielding and safety are important in medical, industrial, and research settings. They are detected by scintillation counters, semiconductor detectors, and gamma‑ray spectrometers. In medicine, gamma‑emitting isotopes are used for imaging and radiotherapy, with diagnostic techniques relying on detecting gamma photons from administered tracers.

Gamma function: a mathematical function that extends the factorial to non‑integer arguments. For complex numbers with positive real part, Γ(z) = ∫0^∞ t^{z−1} e^{−t} dt, and Γ(n) = (n−1)! for positive integers. It provides analytic continuation and appears in probability, statistics, and analysis, often in connection with the beta function and distribution theory.

Gamma distribution: a two‑parameter family of continuous probability distributions with shape α > 0 and scale θ > 0 (or rate β = 1/θ). Its density is f(x; α, θ) = x^{α−1} e^{−x/θ} / (Γ(α) θ^α) for x > 0. It describes waiting times in Poisson processes and is used to model lifetimes, skewed positive data, and certain Bayesian conjugate priors.

Other uses: in physics, gamma denotes quantities such as the Lorentz factor γ = 1/√(1−v²/c²); in imaging, gamma correction refers to nonlinear luminance mapping applied to displays to match perceptual brightness.

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