Gaussian Functions: Summation of Infinite Variations

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Discussion Overview

The discussion revolves around the properties of summing Gaussian functions, specifically whether the summation of an infinite number of different Gaussian functions results in another Gaussian function. The scope includes theoretical considerations and mathematical reasoning related to the behavior of Gaussian functions under summation.

Discussion Character

  • Debate/contested
  • Mathematical reasoning

Main Points Raised

  • One participant suggests that the summation of an infinite number of different Gaussian functions does not yield a Gaussian function, citing the ability to factor out an exponential term.
  • Another participant seeks clarification on whether the summation can be expressed in a specific form involving parameters A, mu, and sigma.
  • A participant expresses skepticism about the validity of the proposed result, implying that it may not hold true.
  • It is argued that summing two Gaussian functions results in a Gaussian with a mean equal to the sum of the means, but an infinite sum could lead to undefined properties such as 'infinite mean' and 'infinite standard deviation.'
  • A question is raised about the validity of the finite case, specifically how the sum of a finite number of different Gaussian functions can still be a Gaussian.
  • One participant challenges the assumption that properties holding for a finite number of cases necessarily extend to an infinite number of cases, prompting a reconsideration of the argument.
  • There is a request for clarification on how to add two different Gaussian functions and whether this can produce another Gaussian function, with a reference to the mathematical representation of Gaussian functions.

Areas of Agreement / Disagreement

Participants express differing views on whether the summation of Gaussian functions retains the Gaussian form, with some arguing against it and others questioning the finite case. The discussion remains unresolved, with multiple competing perspectives present.

Contextual Notes

Participants reference specific mathematical properties and relationships between Gaussian functions, but the discussion does not resolve the implications of summing infinite versus finite cases. There are unresolved assumptions regarding the definitions and conditions under which these properties hold.

pivoxa15
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Is the summation of an infinite number of different (not just different by constants ) Gaussian functions still a gaussian function?

I think not because you can because you can just pull an e^(ax^2) from the series where a is any value as small as needed.
 
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You're asking if whatever A_n, mu_n and sigma_n,

\sum_{n=1}^{\infty}A_n\exp{-\frac{(x-\mu_n)^2}{2\sigma_n^2}}=A\exp{-\frac{(x-\mu)^2}{2\sigma^2}}

for some A, mu and sigma. Is that correct?
 
Yeah. Although I think this result doesn't hold?
 
If you sum two gaussians with mean X and Y (think of them as p.d.f.s) then you get one with mean X+Y. So an infinite sum will, in general, have 'infinite mean'. Similarly, infinite standard deviation. So, no, it is not a Gaussian, and in general won't even exist.
 
But if you sum a finite number of different Gaussian than the sum will still be a gaussian? If so how? how can you get e^a+e^b=e^c where a,b,c are functions that satisfy the exponentials being a gaussian.
 
So, you're arguing that if property P holds for a finite number of things (terms, whatever), then it holds for an infinite number of things? Please, back off and think about that for a while. And I'm not arguing that e^a+e^b=e^c. What are a,b,c, for a start?
 
What I am saying or rather asking is that I don't even see how it would work for the finite case. That is for any two different Gaussians
http://en.wikipedia.org/wiki/Gaussian_function

How do you add them and produce another gaussian?

or even if you take e^2+e^3. Can you make it into e^a for any number a?
 
pivoxa15 said:
What I am saying or rather asking is that I don't even see how it would work for the finite case. That is for any two different Gaussians
http://en.wikipedia.org/wiki/Gaussian_function

How do you add them and produce another gaussian?

or even if you take e^2+e^3. Can you make it into e^a for any number a?
Well, e^{2} + e^{3} = e^{a} \rightarrow a = ln(e^{2} + e^{3}).
 

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