Questions tagged [random]
Questions relating to (pseudo)randomness, random oracles, and stochastic processes.
1,892 questions
0 votes
1 answer
32 views
analysis of the difference in the description of statistical distributions obtained mathematically/physically/computer-generated?
I plot the Gaussian distribution based on the mathematical definition and using the np.random.normal generator: Next, using different interval steps and other parameters, I subtracted both twice to ...
1 vote
0 answers
29 views
Joint measurability Q-Wiener process in L^2
In the book by Da Prato on SPDEs the following is claimed: suppose W is a Q-Wiener process with values in $L^2(\mathbb{R}^d)$. Thus, by the very definition, $W_t(\cdot)$ is a random variable with ...
0 votes
1 answer
36 views
Looking for a crisp argument about the correlation with a complementary event
Assumme a variable $x$ is positively correlated with an event $A$, by which I mean that $\rho_{x,1_{A}} > 0$, where $\rho$ is the correlation coefficient and $1_{A}$ is the indicator function of ...
3 votes
0 answers
53 views
Generating random samples from $\operatorname{GL}_n(\mathbb{F}_p)$
What is the most efficient known algorithm for generating random $n \times n$ invertible matrices with coefficients in the finite field $\mathbb{F}_p$? Of course, I mean sampling from the uniform ...
0 votes
1 answer
98 views
What zeros of a function were once believed to be pseudorandomly distributed but turned out to follow patterns? [closed]
What zeros of a function were once believed to be pseudorandomly distributed but turned out to follow patterns ? I do not consider the GRH or ERH to be valid examples since they are conjectured to be ...
4 votes
2 answers
122 views
Generating uniformly distributed large integer on a given range from smaller random integers
I am writing a c++ library for very large integers. (very large meaning hundreds of digits or more). I want to add a function $Y = \operatorname{randBig}(X)$ to generate a very large, uniformly ...
1 vote
0 answers
55 views
Chinese remainder theorem and randomness related to "unit vectors"
We can take two primes $p_1$ and $p_2$ and consider the smallest non-negative integers $x_1$ and $x_2$ that are equivalent to $x_1 \equiv \left(1 \bmod p_1 \right) \land \left(0 \bmod p_2 \right)$ $...
0 votes
1 answer
80 views
Lazy markov chains mix faster
Consider a reversible markov chain with transition matrix $P$, and eigenvalues $1 = \lambda_1 \geq\lambda_2\dots\geq \lambda_n\geq-1$. Now, the mixing time depends on the eigenvalues with the largest ...
0 votes
0 answers
99 views
Intuition regarding trace $\sigma$-algebras and its uses
Given a random variable $X$ on $(\Omega,\mathcal{F},\mathbb{P})$ and an event $E$, what is the intuition behind the trace $\sigma$-algebra $\sigma(X)\cap E=\{A\cap E:A\in\sigma(X)\}$? What is it used ...
1 vote
1 answer
75 views
Understanding the regularization lemma and what can be said about graphs representing the real word by applying this lemma?
For the most part I understand the mathematical statement of Szemerédi's Regularity Lemma: it states that any large graph's vertices can be partitioned into k parts (groups) of equal or nearly equal ...
2 votes
1 answer
157 views
Trying to recall name of algorithm that generates a "good" random sequence from two poorer ones
I recall seeing an algorithm in Knuth that builds on two unrelated random number generators to make a better one. Use generator 1 to populate a table. Use generator 2 to generate an index and select ...
0 votes
1 answer
58 views
Period of combination of mixed random number generator
Consider the random number generators: \begin{equation*} (i) ~ y_{i+1} = 5y_i + 3 \mod 2^5, \qquad (ii) ~ x_{i+1} = 3x_i \mod 31 \end{equation*} The generators $(i), (ii)$ have periods $32, 30$ ...
1 vote
1 answer
75 views
How is the threshold determined in the Monobit Test, and why is it larger for a 1% significance level than for 5%?
In the Monobit Test for randomness, the threshold for passing or failing is based on a confidence interval. I understand that a 1% significance level (99% confidence) results in a larger threshold ...
2 votes
2 answers
144 views
Generating a uniformly random point on the Sierpinski Triangle?
Is there a math procedure that will theoretically generate a point on the Sierpinski Triangle uniformly at random? There are a bunch of numerical approximate methods I can think of (e.g. just ...
4 votes
1 answer
176 views
How to choose a ''uniformly random'' line inside a circle.
It came up recently in a coding task I was doing that I needed to choose a 'random line' inside of the unit circle. My first thought was to choose two points inside the unit circle at random (i.e. by ...