enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Dirac delta function - Wikipedia

    en.wikipedia.org/wiki/Dirac_delta_function

    A Dirac comb is an infinite series of Dirac delta functions spaced at intervals of T. A so-called uniform "pulse train" of Dirac delta measures, which is known as a Dirac comb, or as the Sha distribution, creates a sampling function, often used in digital signal processing (DSP) and discrete time signal analysis

  3. Green's function - Wikipedia

    en.wikipedia.org/wiki/Green's_function

    Then the integral (′) (′) ′ reduces to simply φ(x) due to the defining property of the Dirac delta function and we have = (, ′) (′) ′ + [(′) ′ (, ′) (, ′) ′ (′)] ^ ′. This form expresses the well-known property of harmonic functions , that if the value or normal derivative is known on a bounding surface, then the ...

  4. Feynman parametrization - Wikipedia

    en.wikipedia.org/wiki/Feynman_parametrization

    Vladimir A. Smirnov: Feynman Integral Calculus, Springer, ISBN 978-3-54030610-8 (Aug.,2006). Vladimir A. Smirnov: Analytic Tools for Feynman Integrals , Springer, ISBN 978-3-64234885-3 (Jan.,2013). Johannes Blümlein and Carsten Schneider (Eds.): Anti-Differentiation and the Calculation of Feynman Amplitudes , Springer, ISBN 978-3-030-80218-9 ...

  5. Bell-shaped function - Wikipedia

    en.wikipedia.org/wiki/Bell-shaped_function

    Some bell shaped functions, such as the Gaussian function and the probability distribution of the Cauchy distribution, can be used to construct sequences of functions with decreasing variance that approach the Dirac delta distribution. [1] Indeed, the Dirac delta can roughly be thought of as a bell curve with variance tending to zero.

  6. Dirac comb - Wikipedia

    en.wikipedia.org/wiki/Dirac_comb

    The graph of the Dirac comb function is an infinite series of Dirac delta functions spaced at intervals of T. In mathematics, a Dirac comb (also known as sha function, impulse train or sampling function) is a periodic function with the formula ⁡ := = for some given period . [1]

  7. Unit doublet - Wikipedia

    en.wikipedia.org/wiki/Unit_doublet

    Approximation of a unit doublet with two rectangles of width k as k goes to zero. In mathematics, the unit doublet is the derivative of the Dirac delta function.It can be used to differentiate signals in electrical engineering: [1] If u 1 is the unit doublet, then

  8. List of mathematical functions - Wikipedia

    en.wikipedia.org/wiki/List_of_mathematical_functions

    Dirac delta function: everywhere zero except for x = 0; total integral is 1. Not a function but a distribution, but sometimes informally referred to as a function, particularly by physicists and engineers. Dirichlet function: is an indicator function that matches 1 to rational numbers and 0 to irrationals.

  9. Duhamel's integral - Wikipedia

    en.wikipedia.org/wiki/Duhamel's_integral

    If a system initially rests at its equilibrium position, from where it is acted upon by a unit-impulse at the instance t=0, i.e., p(t) in the equation above is a Dirac delta function δ(t), () = | = =, then by solving the differential equation one can get a fundamental solution (known as a unit-impulse response function)