Chinese Remainder Theorem Algorithms
Reconstructing an integer from residues, Garner's incremental method, and CRT as a strategy for controlling coefficient growth.
Structured, multi-part guides that take a subject from first principles to applied practice. 3043 pages.
Reconstructing an integer from residues, Garner's incremental method, and CRT as a strategy for controlling coefficient growth.
The Chinese remainder theorem for polynomials, and Lagrange interpolation as its special case.
A consolidated decision guide across the main computational tasks in this collection.
Why class group and unit computation are a single problem, what the combined algorithm produces, and how the results are verified.
Using L-functions and the analytic class number formula to compute or verify class numbers and regulators.
Why intermediate entries in normal form computation grow so violently, how to recognise it, and the three standard mitigations.
A square matrix is nonsingular exactly when its column space is all of C^n: proof, the right-inverse construction and the cost of a deficient column space.
Row-reduce, note the pivot columns, then take those columns of the original matrix: a basis for the column space built from genuine columns rather than reduced ones.
The column space of a matrix is the span of its columns: exactly the set of right-hand sides for which a linear system is consistent, plus the membership test.
The vector space of column vectors, with entrywise definitions of equality, addition and scalar multiplication, and how one vector equation replaces a system.
Conjugation of a column vector entry by entry, and the theorems showing it distributes over vector addition and over scalar multiplication with the scalar conjugated.
The link between curves with complex multiplication and class groups of imaginary quadratic orders, and the Hilbert class polynomial.
Addition, subtraction, multiplication and division of complex numbers, the imaginary unit, reciprocals, and why linear algebra takes its scalars from C.
Gauss composition as the group law on form classes, its practical computation, and reduction between compositions.
What computational algebraic number theory actually computes, why the problems are hard, and how the subject's algorithms fit together.
How number theory, abstract algebra and algorithm analysis combine into a single computational discipline, and how the KEVOS Mathematics library is organised.
Software for computational number theory and algebra, what each is suited to, and how to choose.
Four methods for describing the column space of a matrix: raw columns, pivot columns, the transpose-and-reduce route, and expressing the column space as a null space via extende…
Minors, cofactors and expansion about any row or column: how to evaluate a determinant along the sparsest line, and why triangular matrices collapse to a diagonal product.
Computing eigenvalues as roots of the characteristic polynomial and eigenvectors as null spaces: the determinant test, eigenspaces and basis extraction.
How to compute eigenvalues and eigenvectors of a linear transformation on an abstract vector space: build a matrix representation, solve, then un-coordinatise.
Implementing arithmetic in Z_n: representative choice, reduction after each operation, inversion, and the cost of each primitive.
Finding the minimal polynomial of an element of a polynomial quotient algebra by linear algebra on its powers.
The Berlekamp-Massey algorithm and its Euclidean equivalent for finding the shortest linear recurrence.
Computing the minimal polynomial of a finite field element using conjugates or linear algebra.
Square roots modulo a composite, the four roots for a semiprime, and the equivalence with factoring.
Extracting square roots modulo a prime, the easy case for p congruent to 3 mod 4, and the randomised algorithm in general.
Lifting a square root from a prime to a prime power by Hensel's method, and the special handling powers of two require.
Extracting rank, kernel basis and image basis from an echelon form, and the applications to polynomial factorisation.
How to compute a matrix inverse: the two-by-two determinant formula, the column-by-column view, and Gauss-Jordan reduction of the augmented array [A | I].
The Euclid-style algorithm for evaluating a Jacobi symbol in quadratic time without factoring either argument.
The structure of the unit group of a residue ring of the maximal order, and its computation by decomposition and lifting.
Practical computation with elliptic curves over the complex numbers: periods, the torus map, and heights.
Conditional probability, Bayes' theorem, independence and the distinction between pairwise and mutual independence.
Congruence as an equivalence relation compatible with arithmetic, and the basic manipulation rules including where cancellation fails.
The complex conjugate: definition, the theorems that it respects addition and multiplication, involution, conjugate root pairs and its role in adjoints and inner products.
Conjugates of a finite field element, the norm and trace maps, and their surjectivity onto the subfield.
What follows from the fundamental theorem: gcd and lcm via exponents, irrationality proofs, divisor counting and multiplicative structure.
How to decide whether a linear system has a solution: the augmented-column pivot test, the roles of r, D and F, and why a system has zero, one or infinitely many solutions.
Systematically enumerating number fields of small degree and bounded discriminant, with canonical representatives and completeness arguments.
Continued fractions, convergents as best rational approximations, and the periodic expansion of quadratic irrationals.
Cosets as a partition of a group, Lagrange's theorem, and its consequences for element orders.
Reduction of an elliptic curve modulo a prime, the classification of bad reduction types, and Tate's algorithm.
Cyclic cubic and pure cubic fields as parametrised families, with closed-form invariants that avoid general algorithms.
Cyclic groups, their generators, subgroup structure, and the criterion for the units modulo n to be cyclic.
Recovering exact integer relations from numerical approximations using LLL, and the precision requirements that make the method reliable.
Computing exact determinants by fraction-free elimination, modular methods with Hadamard bounds, and how to choose between them.
Deterministic factorisation over finite fields, the obstacles, and what is known conditionally.