I Strange formulation of Gauss' Theorem

AI Thread Summary
The discussion centers on an alternative formulation of Gauss' Theorem, questioning its mathematical validity and equivalence to the standard form. The proposed formula involves a Gaussian integral, which, upon evaluation, yields the correct result according to one participant. There is curiosity about the usefulness of this alternative expression, with skepticism regarding its practical applications. The formulation interestingly connects two concepts attributed to Gauss: the theorem itself and the Gaussian integral. The conversation highlights the exploration of mathematical relationships within the context of a compendium on Gaussian integrals.
Ssnow
Science Advisor
Messages
573
Reaction score
182
TL;DR Summary
Is this a complicated expression for the ordinary Gauss theorem for the flux of the electric field ?
Hi to all!
The ordinary Gauss theorem states that ##\Phi\left(\vec{E}\right)\,=\, \frac{\sum_{i=1}^{n}q_{i}}{\varepsilon_{0}}## where ##\sum_{i=1}^{n}q_{i}## is the sum of all charges internal of a closed surface and ##\varepsilon_{0}## is the dielectric constant in the empty. Now I ask to the PF if this formula:

##\Phi\left(\vec{E}\right)\,=\, sign{\left(\sum_{i=1}^{n}q_{i}\right)}\cdot \left(\int_{-\infty}^{+\infty}e^{-\frac{\pi\varepsilon_{0}}{\left|\sum_{i=1}^{n}q_{i}\right|}y^2}dy\right)^2##

is equivalent to the previous and if it is mathematically correct.
Thank you!
Ssnow
 
Physics news on Phys.org
It looks good to me; the integral is called a Gaussian integral and if you evaluate it, you get the right answer. I'm wondering where you saw it formulated like this?
 
  • Like
Likes Ssnow
And for what should it be good for?
 
  • Like
Likes Ssnow
In fact it seems not very useful to write le Gauss theorem in this form...
the funny thing is that this formulation relates two result associated to the name of Gauss, respectively the Gauss theorem and the Gaussian integral ... :biggrin:
I encountered this formulation because I am writing a compendium on the Gaussian integral and its generalizations, so I think to put also this nice example ...
Ssnow
 
Consider an extremely long and perfectly calibrated scale. A car with a mass of 1000 kg is placed on it, and the scale registers this weight accurately. Now, suppose the car begins to move, reaching very high speeds. Neglecting air resistance and rolling friction, if the car attains, for example, a velocity of 500 km/h, will the scale still indicate a weight corresponding to 1000 kg, or will the measured value decrease as a result of the motion? In a second scenario, imagine a person with a...
Scalar and vector potentials in Coulomb gauge Assume Coulomb gauge so that $$\nabla \cdot \mathbf{A}=0.\tag{1}$$ The scalar potential ##\phi## is described by Poisson's equation $$\nabla^2 \phi = -\frac{\rho}{\varepsilon_0}\tag{2}$$ which has the instantaneous general solution given by $$\phi(\mathbf{r},t)=\frac{1}{4\pi\varepsilon_0}\int \frac{\rho(\mathbf{r}',t)}{|\mathbf{r}-\mathbf{r}'|}d^3r'.\tag{3}$$ In Coulomb gauge the vector potential ##\mathbf{A}## is given by...
Thread 'Griffith, Electrodynamics, 4th Edition, Example 4.8. (First part)'
I am reading the Griffith, Electrodynamics book, 4th edition, Example 4.8 and stuck at some statements. It's little bit confused. > Example 4.8. Suppose the entire region below the plane ##z=0## in Fig. 4.28 is filled with uniform linear dielectric material of susceptibility ##\chi_e##. Calculate the force on a point charge ##q## situated a distance ##d## above the origin. Solution : The surface bound charge on the ##xy## plane is of opposite sign to ##q##, so the force will be...
Back
Top