In mathematics, Parseval's theorem usually refers to the result that the Fourier transform is unitary; loosely, that the sum (or integral) of the square...
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Discrete Fourier transform (redirect from Circular convolution theorem)
the star denotes complex conjugation. The Plancherel theorem is a special case of Parseval's theorem and states: ∑ n = 0 N − 1 | x n | 2 = 1 N ∑ k = 0 N...
76 KB (12,338 words) - 04:38, 31 July 2025
Fourier transform (redirect from Fourier shift theorem)
Plancherel, it is still often referred to as Parseval's formula, or Parseval's relation, or even Parseval's theorem. See Pontryagin duality for a general formulation...
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square-integrable over the interval ( 0 , ∞ ) {\displaystyle (0,\infty )} , then Parseval's formula holds: ∫ 0 ∞ f 1 ( x ) f 2 ( x ) d x = 1 2 π i ∫ c − i ∞ c + i...
33 KB (4,679 words) - 18:09, 17 June 2025
Fourier series (redirect from Fourier theorem)
p_{N}(x)=\sum _{n=-N}^{N}p[n]\ e^{i2\pi {\tfrac {n}{P}}x}.} Parseval's theorem implies that: Theorem—The trigonometric polynomial s N {\displaystyle s_{N}}...
72 KB (11,152 words) - 20:53, 30 July 2025
{d} r=\int _{0}^{\infty }F_{\nu }(k)G_{\nu }(k)\,k\,\mathrm {d} k.} Parseval's theorem, which states ∫ 0 ∞ | f ( r ) | 2 r d r = ∫ 0 ∞ | F ν ( k ) | 2 k...
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In mathematical analysis, Parseval's identity, named after Marc-Antoine Parseval, is a fundamental result on the summability of the Fourier series of a...
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\max(-\beta _{1},\alpha _{2})<c<\min(-\alpha _{1},\beta _{2})} . Then Parseval's theorem holds: ∫ − ∞ ∞ f 1 ( t ) ¯ f 2 ( t ) d t = 1 2 π i ∫ c − i ∞ c + i...
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Energy (signal processing) (section Parseval's theorem)
correct in SI units for spectral energy density. As a consequence of Parseval's theorem, one can prove that the signal energy is always equal to the summation...
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Marc-Antoine Parseval des Chênes (27 April 1755 – 16 August 1836) was a French mathematician, most famous for what is now known as Parseval's theorem, which...
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x(t)} is a square-integrable function) allows applying Parseval's theorem (or Plancherel's theorem). That is, ∫ − ∞ ∞ | x ( t ) | 2 d t = ∫ − ∞ ∞ | x ^...
37 KB (5,896 words) - 00:17, 5 August 2025
Generalized Fourier series (section Parseval's theorem)
_{n=0}^{\infty }|c_{n}|^{2}\leq \int _{a}^{b}|f(x)|^{2}w(x)\,dx.} Parseval's theorem usually refers to the result that the Fourier transform is unitary;...
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generalization of Parseval's theorem; often used in the fields of science and engineering, proving the unitarity of the Fourier transform. The theorem states that...
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_{M}} A special case of the Parseval's theorem is when the two multi-dimensional signals are the same. In this case, the theorem portrays the energy conservation...
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Parallelogram law Parseval's identity – The energy of a periodic function is the same in the time and frequency domain. Ptolemy's theorem – Relates the 4...
95 KB (12,798 words) - 21:40, 4 August 2025
Lauricella's theorem (functional analysis) Paley–Wiener theorem (Fourier transforms) Parseval's theorem (Fourier analysis) Plancherel theorem (Fourier analysis)...
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function, and finally applying the inverse Fourier transform. Hence Parseval's theorem easily shows that the Hilbert transform is bounded from L 2 {\displaystyle...
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such as LUFs. The RMS can be computed in the frequency domain, using Parseval's theorem. For a sampled signal x [ n ] = x ( t = n T ) {\displaystyle x[n]=x(t=nT)}...
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Exponential sum Dirichlet kernel Fejér kernel Gibbs phenomenon Parseval's identity Parseval's theorem Weyl differintegral Generalized Fourier series Orthogonal...
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theorems, including Parseval's theorem. For this reason, keeping the full name of "Rayleigh Theorem for Eigenvalues" avoids confusions. The theorem,...
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f ) {\displaystyle H(f)} or in the time domain by exploiting the Parseval's theorem with the system impulse response h ( t ) {\displaystyle h(t)} . If...
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Fourier transform (with proper normalization). This follows from Parseval's theorem. Quantum logic gates are unitary operators. Not all gates are Hermitian...
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Spherical harmonics (section Addition theorem)
related to its spectral coefficients by a generalization of Parseval's theorem (here, the theorem is stated for Schmidt semi-normalized harmonics, the relationship...
75 KB (12,488 words) - 23:57, 29 July 2025
satisfy Parseval's theorem. (Other, non-unitary, scalings, are also commonly used for computational convenience; e.g., the convolution theorem takes on...
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{\displaystyle \epsilon } , can be derived using Plancherel theorem or Parseval's theorem for the Fourier transform. If we substitute in the expression...
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Sobolev inequality (redirect from Kondrakov theorem)
n-ball. Choosing ρ to minimize the sum of (1) and (2) and applying Parseval's theorem: ‖ u ^ ‖ L 2 = ‖ u ‖ L 2 {\displaystyle \|{\hat {u}}\|_{L^{2}}=\|u\|_{L^{2}}}...
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Multiplier (Fourier analysis) (redirect from Marcinkiewicz multiplier theorem)
which has the largest multiplier space. This is the easiest case. Parseval's theorem allows to solve this problem completely and obtain that a function...
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This form of the Riesz–Fischer theorem is a stronger form of Bessel's inequality, and can be used to prove Parseval's identity for Fourier series. Other...
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operator Fourier inversion theorem Sine and cosine transforms Parseval's theorem Paley–Wiener theorem Projection-slice theorem Frequency spectrum Discrete...
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Bessel's inequality (category Theorems in functional analysis)
finite}}{\Bigr \}}\leq \lVert x\rVert ^{2}.} Cauchy–Schwarz inequality Parseval's theorem "Bessel inequality - Encyclopedia of Mathematics". Saxe, Karen (2001-12-07)...
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