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0 votes
0 answers
36 views

Preservation of strict log-concavity under convolution

I have spent an embarrassing amount of time trying to prove or disprove any of this. I am aware that a similar question was posted in 2014, but since I couldn't make anything out of the two sources ...
Jacob's user avatar
  • 13
0 votes
0 answers
61 views

Probability density function of three independent random variables

I will try to describe the question first and how i solve the problem. Here we have three independent random variable $X,Y,Z$ and $S_3=X+Y+Z$, the probability density function of three variable are ...
Joe_LL's user avatar
  • 1
1 vote
1 answer
68 views

"Deconvoluting" the sum of independent random variables

I encountered the following question in my research. See here for some background, but this post should be self-contained. Suppose $X$ follows a discrete uniform distribution on $m$ points $\{X_1, ...
nalzok's user avatar
  • 836
1 vote
1 answer
71 views

How does this density function make sense?

Let $X$ be an exponentially distributed random variable with parameter $\beta>0$ and let $Y$ be a random variable with $P(Y=0)=1-p$ and $P(Y=1)=p$, where $0<p<1$. Assume that $X$ and $Y$ are ...
Selby Ching's user avatar
0 votes
0 answers
55 views

W.s.s. Gaussian process in LTI, probability of the output signal

Let {${X(t); t\in ℝ}$} be a wide sense stationary Gaussian process with mean $\mu_X = 1$ and power spectral density $$S_X(f) = \begin{cases} 1, \ \text{if} \ |f| < 5; \\ 0, \ \text{otherwise}. \...
AANICR's user avatar
  • 93
1 vote
1 answer
255 views

Finding distribution and density function of $X^2/(X^2+Y^2)$ where $X,Y∼N(0,1)$

I have two random independent standard normal variables $X,Y∼N(0,1)$. How can I find the distribution of $\,\dfrac{X^2}{X^2+Y^2}\;?$ I know that if we talk about only $X^2$ then it will be a Chi-...
Drekhem's user avatar
  • 11
0 votes
1 answer
46 views

Probability density of $X_1 − 2X_2$, where $X_1, X_2$ independent and exponentially distributed.

Problem Consider $X_1, X_2 \sim \varepsilon(1)$ independent and define $T = X_1 - 2X_2$. I want to calculate the probability density function (pdf) of $T$, denoted by $f_T$, which can be obtained by ...
Lime91's user avatar
  • 151
1 vote
1 answer
538 views

PDF of $|X-Y|$ when X and Y are independent uniform on $\left[0,l\right]$

pretty much trying to solve the question in the title, what I tried is: consider $Z=\left|Y-X\right|$, and try to compute $F_{Z}\left(t\right)=1-P\left(Z>t\right)=1-\left(P\left(X-Y>t\right)+P\...
Abzikro's user avatar
  • 121
0 votes
0 answers
78 views

How to prove that probability density function of the sum of 2 independant variable is equal to their convolution?

The probability density function of the sum of two independent random variables is the convolution of their individual probability density functions. What is the simplest demonstration that proves ...
schlebe's user avatar
  • 139
0 votes
2 answers
98 views

Density of $X_1 + X_2$ using convolution

Let $X_1$ and $X_2$ be independent random variables continuously uniformly distributed on $[−1, 1]$ and $[0, 5]$, respectively. Determine, with intermediate steps, the density of $X_1 + X_2$. To do ...
Mary Star's user avatar
  • 14k
0 votes
0 answers
24 views

For any probability density function f, does it always exists another probability g such that f = g∗g? (* means convolution)

I just learned the theory of convolution between functions, for a probability density function, is there always existing another function g such that f = g * g (convolve with itself?)
daily dreamers's user avatar
0 votes
1 answer
91 views

If $f_{X,Y}(x,y)=4e^{-2(x+y)}$, find the pdf of $X+Y$

I need to find the pdf of $X+Y$. I tried Jacobian method and Cdf method but two outputs are different. Can someone plz help me solve this problem? These are my solution process. jacobian-> $Z=X+Y$ ...
Godchi's user avatar
  • 29
2 votes
0 answers
621 views

Convex combination of random variables

Let $X, Y$ two independent real random variables. If I define the distance of the distribution (i.e. the cumulative density function) of $X$ with a target distribution $F$ as $$\sup_t |F_X(t)-F(t)|$$ ...
Davide Maran's user avatar
  • 1,199
0 votes
2 answers
315 views

Convolution $\arcsin$ pdf's: $\;\displaystyle \int \frac{1}{\pi \sqrt{1-\tau^{2}}} \cdot \frac{1}{\pi \sqrt{1-(R-\tau)^{2}}} \ d \tau$

Regarding topic: SE I encountered a convolution of two identical $\arcsin$ distributions. The probability density function $pdf$ for $R \in [−1,1]$ in this context is: $$f(R)=\frac{1}{\pi \sqrt{1-R^2}}...
Vincent Preemen's user avatar
1 vote
1 answer
387 views

Convolution of two independent uniform variables

Question: Let's say $X$ and $Y$ are two independent random variables with $Uniform (0,3)$ distribution. What is the probability density function of $X+Y$? In solution, it is told to use convolution ...
Kevin's user avatar
  • 11

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