Prove the property of Dirac's Delta

In summary, the conversation discusses proving a property of the Dirac delta function, using information from John David Jackson's Classical Electrodynamics book and other sources, such as Wikipedia. The suggested approach involves using the scaling property of the delta function and simplifying the function near its zeroes. The conversation ends with a thank you to clamtrox for the helpful information.
  • #1
phy07
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  • #2
Let [tex]\lbrace x_i \rbrace [/tex]be the zeroes of function f(x). Near the zeroes, you can write the function as [tex]f(x) = f'(x_i)(x-x_i) + O(x-x_i)^2. [/tex] As the Dirac delta is entirely localized at xi, you can just drop all higher order terms and it's still exact. Then you can use the scaling property of delta function, http://en.wikipedia.org/wiki/Dirac_delta_function#Scaling_and_symmetry
 
  • #3
Ok. Thank you clamtrox.
 

1. What is Dirac's Delta function?

Dirac's Delta function is a mathematical function that is defined as zero for all values except at the origin, where it is infinity. It is commonly used in physics and engineering to represent a point source or impulse.

2. How do you prove the property of Dirac's Delta?

The property of Dirac's Delta can be proven using the following integral: ∫f(x)δ(x-a)dx = f(a). This integral shows that the Delta function acts as a sampling or filtering function, picking out the value of f at the point a.

3. What are the applications of Dirac's Delta function?

Dirac's Delta function has many applications in physics and engineering, including signal processing, quantum mechanics, and differential equations. It is also used to represent point charges and point masses in electromagnetism and mechanics, respectively.

4. Can Dirac's Delta function be approximated by other functions?

Yes, Dirac's Delta function can be approximated by other functions, such as the rectangle function or the Gaussian function. These approximations are often used in numerical calculations or simulations where the Delta function cannot be directly used.

5. What is the physical interpretation of Dirac's Delta function?

The physical interpretation of Dirac's Delta function is that it represents a point source or impulse. This means that it has an infinite value at a single point and zero value everywhere else. It is often used to model the behavior of a system when a sudden, infinitely large force or disturbance is applied.

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