I Dimensional Analysis Poisson Equation

AI Thread Summary
The discussion focuses on using dimensional analysis to estimate the order of magnitude of the electrostatic potential from a given charge density profile ρ(x) in the context of Poisson's equation in one dimension. It highlights that the electrostatic potential φ can be influenced by arbitrary constants, allowing for shifts without violating the equation. The relationship between charge density and potential is emphasized, suggesting that understanding the scaling of ρ(x) can provide insights into φ. The conversation underscores the importance of recognizing the flexibility in defining potential while adhering to the mathematical framework of Poisson's equation. Overall, dimensional analysis serves as a useful tool for approximating electrostatic potential in electrostatics.
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Suppose I am given some charge density profile ρ(x). Poisson's equation in 1D reads

d2φ/dx2 = ρ(x)/ε

Is there a simple way to see what the order of magnitude of the electrostatic potential should be from a dimensional analysis?
 
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aaaa202 said:
Suppose I am given some charge density profile ρ(x). Poisson's equation in 1D reads

d2φ/dx2 = ρ(x)/ε

Is there a simple way to see what the order of magnitude of the electrostatic potential should be from a dimensional analysis?
The potential is arbitrary. You can shift it by a constant and still satisfy the Poisson equation.
 
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