Difference between revisions of "Noise stability"

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(Created page with " == Definition == f:{− 1 , 1 } n → R and ρ ∈ [ − 1 , 1], the noise stability of f at ρ is Stab ρ [f] = E[f(x)f(y)]. ( x,y ) ρ -correlated")
 
(Definition)
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== Definition ==
 
== Definition ==
f:{1 , 1 } n R and ρ ∈ [ − 1 , 1], the noise stability of f at ρ is
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For <math>f:\{-1,1\}^{n}\rightarrow\mathbb{\mathbb{R}} </math> and <math>\rho∈[−1,1]</math>, the noise stability of <math>f</math> at <math>\rho</math> is <math>Stab_{\rho}[f]=\underset{\underset{\rho-correlated}{(x,y)}}{\mathbb{E}}[f(x)f(y)]</math>,
Stab ρ [f] = E[f(x)f(y)].
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where <math> x </math> and <math>y </math> are <math>\rho</math>-correlated if <math> y_{i}=\begin{cases}
( x,y )
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x_{i} & with\space prabability\space \frac{1}{2}+\frac{1}{2}\rho\\
ρ -correlated
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-x_{i} & with\space prabability\space \frac{1}{2}-\frac{1}{2}\rho
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\end{cases}</math>

Revision as of 07:41, 23 September 2019

Definition

For [math]f:\{-1,1\}^{n}\rightarrow\mathbb{\mathbb{R}} [/math] and [math]\rho∈[−1,1][/math], the noise stability of [math]f[/math] at [math]\rho[/math] is [math]Stab_{\rho}[f]=\underset{\underset{\rho-correlated}{(x,y)}}{\mathbb{E}}[f(x)f(y)][/math], where [math] x [/math] and [math]y [/math] are [math]\rho[/math]-correlated if [math] y_{i}=\begin{cases} x_{i} & with\space prabability\space \frac{1}{2}+\frac{1}{2}\rho\\ -x_{i} & with\space prabability\space \frac{1}{2}-\frac{1}{2}\rho \end{cases}[/math]