A law earns its place by clarifying how a pattern is produced, not only by naming it.
Mathematics & Probability
Formal laws and statistical regularities involving uncertainty, distributions, games, and quantitative structure.
Which patterns follow from structure and uncertainty?
- Working scale
- Axioms to real datasets
- Primary lens
- Proof + statistical inference
The field at a glance.
Each subfield has a distinct object of study. Published areas are active now; planned areas show how the collection will grow.
Events, uncertainty, conditioning, and long-run behavior.
Inference, estimation, testing, and uncertainty in data.
Recurring shapes in how quantities and frequencies are spread.
Strategic choices made in response to other decision-makers.
In Mathematics & Probability
Every guide includes meaning, mechanism, applications, limitations, related concepts, and traceable references.
Statistical regularity
Benford's Law
In many naturally occurring datasets, the leading digit is 1 far more often than 9, following a logarithmic distribution.
Fundamental probability theorem
Law of Large Numbers
Sample averages, convergence, weak and strong forms, finite-sample uncertainty, and the gambler fallacy.
Conditional probability theorem
Bayes' Theorem
Evidence updates a prior belief by comparing how expected that evidence is under competing possibilities.
Asymptotic statistical theorem
Central Limit Theorem
Under broad conditions, properly standardized sums or averages of many independent contributions approach a normal distribution.
Strategic equilibrium concept
Nash Equilibrium
A strategy profile is a Nash equilibrium when no player can improve their expected payoff by changing strategy alone while the others keep theirs fixed.
Scale-free functional relation and tail model
Power Law
A quantity follows a power law when relative changes in scale produce proportional changes governed by a fixed exponent, often creating heavy-tailed variation.
Social-choice impossibility theorem
Arrow's Impossibility Theorem
With at least three alternatives, no rank-order aggregation rule can satisfy unrestricted domain, Pareto efficiency, independence of irrelevant alternatives, and non-dictatorship simultaneously.
Collision-probability result
Birthday Paradox
A group needs surprisingly few people before the probability that at least two share a birthday becomes substantial, because the number of possible pairs grows quadratically.
Distribution-free probability bound
Markov's Inequality
For any nonnegative random variable, the probability of exceeding a positive threshold cannot be greater than the mean divided by that threshold.
Probability inequality
Chebyshev's Inequality
For any distribution with finite variance, the probability of being at least k standard deviations from the mean is no greater than 1/k squared.
Statistical selection effect
Regression to the Mean
When two measurements are imperfectly correlated, units selected for an extreme first value tend to be less extreme on a subsequent measurement.
Aggregation reversal
Simpson's Paradox
A trend that appears within every relevant group can weaken, disappear, or reverse after the groups are combined with different weights.
Conditional-probability problem
Monty Hall Problem
With three doors, a prize placed uniformly, and a host who always reveals a goat behind an unchosen door, switching wins with probability two thirds.
Collective-decision theorem
Condorcet Jury Theorem
If voters independently choose between two alternatives and each is more likely than not to be correct, majority accuracy approaches one as the group grows.
No field stands alone.
These connections show where the domain borrows methods, mechanisms, or evidence from the rest of the library.
Scientific status, operating range, evidence quality, and common misuse stay visible.
Original publications, official records, and serious scholarship take priority.