
What Exactly is Dirac's Delta Function? - Physics Forums
Aug 29, 2025 · Dirac’s delta function is considered (notation for) a distribution. Specifically it is (and its derivatives are) expressed in terms of the Radon-Nikodym derivative (s) of the measure defined by …
Proof of Dirac Delta's sifting property - Mathematics Stack Exchange
First a small remark : the dirac delta is not strictly speaking a function, it's called a distribution. It's often defined as being the distribution such that $\int f (x) \delta (x) dx = f (0)$. Using that definition, your …
What is the convolution of a function $f$ with a delta function $\delta$?
Sep 12, 2024 · The delta "function" is the multiplicative identity of the convolution algebra. That is, $$\int f (\tau)\delta (t-\tau)d\tau=\int f (t-\tau)\delta (\tau)d\tau=f (t)$$ This is essentially the definition of …
Dirac Delta Function of a Function - Mathematics Stack Exchange
Using this definition and the fact that the $\delta$-distribution is half of the second derivative of the absolute value function, one can give a rigorous proof of the formula in the query.
Dirac's Delta function - Mathematics Stack Exchange
Aug 25, 2019 · On Wikipedia, the definition of the dirac delta function is given as: Suppose I have a function where at two points, the function goes to infinity. Given that the distance between the two …
Derivative of the Dirac delta function - Mathematics Stack Exchange
Mar 9, 2023 · The Dirac delta is defined as a distribution by $$ \langle \delta_0,\varphi\rangle = \varphi (0). $$ The compact support is actually not needed for $\varphi$ because the value here just …
Two Dimension Delta Function - Mathematics Stack Exchange
Jun 13, 2020 · The left hand side is the correct two-dimensional Delta function around (0,0) in Cartesian coordinates. Now this can indeed be written in terms of polar coordinates, however your right hand …
Derivative of a Delta function - Mathematics Stack Exchange
Jul 16, 2013 · Physicists' $\delta$ function is a peak with very small width, small compared to other scales in the problem but not infinitely small. So what I do to such inconsistency of $\delta$ function …
Delta (Dirac) function integral - Mathematics Stack Exchange
Mar 27, 2013 · Since the $\delta$ function doesn't actually exist as a function (all functions $\mathbb {R}\to\mathbb {R}$ which are zero everywhere except at a point have Riemann integral equal to $0$, …
Fourier Representation of Dirac's Delta Function
Sep 4, 2020 · From what I currently understand about this topic the equation above should be the Fourier representation of the Dirac's Delta Function, however I don't see how to prove it. …