parallel computation, 587, 603

parallel postulate, 42, 84–88, 90, 94

parity function, 588

partial derivative, 33

partial differential equations (PDEs), 34–35, 187, 455–83, 681–82, 993–94; criticality of, 479–80; dispersive, 236, 468, 471; elliptic, 468–71, 681–83; fully nonlinear, 462; homogeneous linear, 457; hyperbolic, 468–70, 490; inhomogeneous linear, 457–58; linear, 51, 458, 471–72; local solvability of, 471; nonlinear, 457; order of, 461; parabolic, 468, 470–71; quasilinear, 462; regular, 480, 482; semilinear, 462; subcritical, 479–80, 482; supercritical, 479–80, 482; symbols of, 682–83

partial differential operators, 239

partition functions, 62, 529, 667, 669

partitions: of natural numbers, 555, 797, 807, 994–95; of sets, 558

Pascal, Blaise, 741–42

Pascal’s triangle, 741

Pasch, Moritz, 137–39

path integral, 38, 526–28, 541, 545

Peano, Giuseppe, 111, 128, 138, 701, 787–88, 795

Peano arithmetic, 138, 151, 154, 258–59, 638, 701, 787, 819; first-order, 259, 638

Pell equations, 98, 255, 315, 317, 706

Penrose, Roger, 829

Penrose staircase, 951

Penrose filings, 829

Penrose’s incompleteness theorem, 492

percolation, 662–66

Perelman, Grigori, 281, 388, 401–3, 406, 440, 461, 714, 970

perfect matchings in a graph, 566, 587, 596

perfect number, 104

perfect phylogeny problem, 846

perfect sets, 619, 632

periodic orbits, 495, 498–99

periodic points, 498–99

permanent of a matrix, 591

permutation matrices, see matrices, permutation

permutations, 174, 259–61, 420, 558

Perron’s formula, 336

perspective, 945–46

perturbation theory, 527–28, 541

phase of a Fourier coefficient, 859

phase problem in crystallography, 829

phase space, 286

phase transitions, 7, 261, 573, 657, 660–64, 667–68, 845

phenomenological equations, 480–81

philosophasters, 935

phylogenetic tree, 846

π, 60, 79, 108–9, 222–23, 261–62, 325, 748; continued fraction for, 192; formula for, 262, 998–99; hexadecimal expansion of, 262, 998–99; transcendence of, 81, 223, 262

Picard iteration method, 465, 470

pigeonhole principle, 167, 567; proof complexity of, 591–94

Pisot number, 828

pivoting in Gaussian elimination, 607

planar graphs, see graphs, planar

Plancherel theorem, the, 207, 212, 261, 427, 453, 686

plane waves, 205–7, 236

Plateau problem, 458

Plato, 83–84

Platonic solids, 52, 84, 187, 189

Platonism, 148, 155

Poincaré, Jules Henri, 42, 93–94, 146–47, 152, 209, 215, 400, 403, 432, 484, 495–96, 690, 714, 722, 727–28, 785–87, 802, 946–48

Poincaré conjecture, 141, 219, 403, 714, 786; in four dimensions, 404; in more than four dimensions, 404–5

Poincaré duality, 189

Poincaré map, 495

Poincaré quantum group, 275

Poincaré transformations, 457, 478

Poincaré’s recurrence theorem, 690–91

point at infinity, 41, 43, 267, 356, 366, 370, 386, 721

Poisson, Siméon-Denis, 757

Poisson bracket, 286, 525–26, 541

Poisson distribution, 264

Poisson equation, 286–87, 457–58, 483, 492

poker, electronic, 601–2, 895

polar convex body, see duality, of convex bodies

polarization identity, 268

Pölya, George, 358, 831, 959

Pölya-Redfield enumeration, 559–61, 831

polynomial equations, 49–50

polynomial ring, 24

polynomial time, 169

polynomial-time algorithms, 197–98, 350, 353, 355, 551, 579, 873–74, 880; for primality testing, 353

polynomial-time reducibility, 582–83, 591

polynomials, 284, 326, 328–29, 363–65, 738; approximation by, 253

polytopes, 52

Pontryagin classes, 394

Pontryagin duality, see duality, Pontryagin

position operator, 286

positional system for numbers, 77

posterior distributions, 160, 920, 926–27

postmodernism, 967–69

potential theory, 283, 760

potentials in complex dynamics, 503–4

Potts model, 669

power series, 38, 122, 126, 144, 201, 308, 368, 752

power-set axiom, 157, 314, 620–21

preconditioning a system of linear equations, 609

predicativity, 146–47, 149

presentations of groups, 433–34

primality testing, 351–53, 595; polynomial-time, 352–53; randomized, 351–52, 892

prime factorization, see factorization of integers, into primes

prime ideals, 143, 323, 378

prime number theorem, 63, 338, 346, 356, 714–15, 729, 804

prime numbers, 63, 69–70, 75, 319, 325, 332–36, 338–41, 348–53, 357, 714–15; distribution of, 229, 283–84, 356–59; gaps between, 66, 342–45

primitive polynomials, 888

primitive recursive functions, 111–12

Princet, Maurice, 947

principal ideals, 58, 221, 322–23

Principia Mathematica (Newton), 87, 136, 743, 750

Principia Mathematica (Whitehead and Russell), 147, 149, 781, 795

prior distribution, 160, 920, 926

prisoner’s dilemma, 901

private goods, 901

probabilistic computation, 269–71

probabilistic method, 197, 563, 572

probabilistic proof systems, 596–99

probabilistically checkable proofs, 598–99

probability, 7, 917

probability amplitudes, 269–71

probability distributions, 263–71, 917

probability theory: foundations of, 793, 795, 814–15

probability thresholds, 661–62

Proclus, 85

products, 23–24

projections, 43, 240–41, 295, 422; Mercator, 978; orthogonal, 240–41, 295, 518; stereographic, 169, 401

projective determinacy, axiom of, 632–34

projective geometry, 43, 92, 169, 173, 187, 267, 356, 388, 400

projective orthogonal groups, 688

projective representations, 544

projective sets, 628, 631–32

projective spaces, 161, 230, 267, 300, 313, 365

projective special linear groups, 41, 43, 688

projective unitary groups, 688

projective varieties, see varieties, projective

proof complexity, 591–94

proofs, 74, 129–42, 622, 637, 642, 646; by contradiction, 150

propagation of singularities, 467, 469

proper time, 485

propositional logic, see logic, propositional

propositions, 73

protein folding, 841

protein structure, 835

pseudorandomness, 116, 600–602

pseudosphere, 92

PSPACE, see complexity classes

public goods, 901

public-key cryptography, 602, 890–95

pullbacks, 180, 410

pure states, 270

Putnam, Hilary, 50

Pythagoras, 18, 733–34, 980

Pythagorean comma, 936

Pythagorean triples, 364, 691

Pythagorean tuning system, 936

QR factorization, 607–8

quadratic convergence, see convergence, quadratic

quadratic equations, 49, 133, 193, 708

quadratic fields, 254

quadratic forms, 267–69, 317, 319; binary, 320–23, 325; positive definite, 268

quadratic reciprocity, see reciprocity, quadratic

quadratic residues, 104, 317, 325, 327, 339

quadratic sieve method, 354–55

quadratic variation of a martingale, 652

quadratic-like mappings, 508

quadrature, 292, 609, 614; Clenshaw-Curtis, 609; Gaussian, 292, 609

quadric surface, 62

quadrivium, the, 935

quantifiers, 14, 31, 149, 621, 635–36, 638, 640–41; elimination of, 640–44

quantization, 526, 528

quantum computation, 269–72

quantum field theories, 528–29, 542–48; topological, 227

quantum groups, 272–75

quantum mechanics, 269, 287, 513, 526, 539; operator formulation of, 526

quartic equations, 99, 101, 326, 709, 737

quasi-conformal mappings, 713

quasi-isometry, 443–45

quasi-Newton methods, 613

quasicrystals, 828–29

quaternions, 82, 105, 276–79, 389, 765

Quechua numeration, 984–85

quintic equations: insolubility of, 50, 101, 327, 708–10

quotients, 24–26, 28, 257, 284; of groups, 26; of rings, 284

Rényi, Alfréd, 572, 660

radial lines, 504

radical of a positive integer, 361, 681

Radon transform, 297, 307

Ramanujan, Srinivasa, 62, 64, 268, 729, 797, 807–8

Ramanujan conjecture, 729, 732

Ramanujan graphs, 198

Ramanujan-Nagell equation, 254

Ramanujan’s ternary form, 269

Ramanujan’s Lost Notebook, 808

ramification, 323, 330

Ramsey theory, 215, 562, 567–68, 573–74, 627, 639, 702

random graphs, 572, 645–46, 660–62

random matrices, 345, 359

random packing, 836

random restriction method in computational complexity, 588

random trees, 655–57

random variables, 265–67

random walks, 61, 72, 198–99, 648–51, 679

random-cluster model, 669

randomized algorithms, 116, 351, 595, 892

randomness, 115–16, 199, 269, 361

randomness extractors, 599

range of a function, 11

rank, 245; of a set, 621; of a vector bundle, 393

Raphson, Joseph, 110

rapid mixing, 199, 679

rational functions, 126, 193

rational numbers, 17–18, 82, 126–27, 144, 171, 242, 246, 284, 316, 622; approximation by, 192, 222, 315–16, 710

ratios, 79

reaction-diffusion equations, 219, 844

real closed fields, 643

real division algebra, 395

real numbers, 18, 80–82, 102, 123, 127–28, 144, 616, 622–25, 171, 627, 242, 630, 246, 635, 275, 639–40, 643–45, 698, 776

real projective line, 409

reciprocity: Artin’s law of, 720, 812–13; higher, 104, 719–20, 812–13; quadratic, 104, 718–20, 812; quartic, 104, 719

recurrence formulas, 110, 552

recursion, 66, 113–14, 552

recursive functions, 111–13

recursive sets, 439–40

recursively enumerable sets, 439–40, 638–39

recursively presentable group, 439

reductio ad absurdum, 150

reductive groups, 430

Reed-Solomon codes, 883–86

reflexive relations, 12

refutation systems, 593

regular cardinals, see cardinals, regular

regular polyhedra, 52

regular polytopes, 53

regular primes, 692

regularity of solutions to partial differential equations, 481

relations, 11–12, 932

relative consistency proofs, 623

relativity, 539; equivalence principle in, 486, 488; general, 164, 172, 483–93; principle of, 484, 487; special, 483–85

repelling orbits, 502

representation ring of a group, 423

representation varieties, 417–18

representations, 207, 274, 279, 420–24, 783–84; decomposable, 427; induced, 424; irreducible, 279, 422–29, 515–16, 561; linear, 234, 279; regular, 423, 516–18, 520; unitary, 313, 514–16

residue mod m, see modular arithmetic

resolution of singularities, 369

resolution rule, 594

restriction mapping problem, 839

retractions, 694

Reuleaux triangle, 978

rhythmic augmentation and diminution, 938

Ribet, Ken, 692

Ricci curvature, see curvature, Ricci

Ricci flow, 219, 279–81

Ricci tensor, 164, 172

Richard’s paradox, 146

Riemann, Georg Friedrich Bernhard, 36, 91–92, 124–25, 127, 137, 143, 282, 284, 336–37, 356–58, 475, 729, 771, 774–76, 780, 782, 929, 947–48

Riemann curvature tensor, 488

Riemann hypothesis, 63, 68, 229, 337–38, 356–58, 714–15; for curves, 356, 730–31; generalized, 229, 340–41, 348, 729–30

Riemann integration, see integration, Riemann

Riemann mapping theorem, 728, 774–75

Riemann sphere, 282, 370, 389, 412, 500, 723

Riemann surface bundle, 414

Riemann surfaces, 209, 282–83, 300, 408, 411–14, 416, 529–30, 723, 728–29, 775, 805, 816; families of, 413–14, 417

Riemann zeta function, 38, 228–29, 283–84, 336, 344, 356, 359, 685, 715, 775

Riemann-Roch theorem, 683, 724, 775, 820

Riemannian manifolds, 218, 280, 296–97, 394, 444

Riemannian metrics, 46–47, 172, 280, 300, 311, 407, 775

Riesz, Frigyes (Frédéric), 689–90, 798–99

Riesz representation theorems, 185, 791, 798

rigid transformations, 39

rigidity theorems, 442, 444, 703, 711

rigor in mathematics, 117–29, 137, 930–31

rings, 22, 24, 57, 104–5, 108, 221, 254, 284–85, 317–19, 329, 376–77, 391, 776; graded, 391; of polynomials, 108

risk, 903, 914–15, 918

risk-neutral pricing, 912

road rage, 918

Robbin, Tony, 952–53

Robertson-Seymour theorem, 725

Robinson, Abraham, 128, 822–23

Robinson, Julia, 50

Rodriguez’s formula, 291

Rogers-Ramanujan identities, 557, 807

root systems, 233–34

roots: of polynomials, 66, 101; of unity, 327–28

rotational invariance: of Brownian motion, 650, 653; of normal distribution, 266

Roth’s theorem, 222, 681, 711

rounding errors, 606–7

RSA algorithm, 602, 891

Ruffini, Paolo, 101

rules of inference, 84, 140, 152, 700

Runge-Kutta method for numerical solution of ordinary differential equations, 610

Russell, Bertrand Arthur William, 128, 145–49, 781, 795–96, 929, 933–34

Russell, John Scott, 234–35, 237

Russell’s paradox, 128, 145, 171, 619, 779, 781, 795, 807

Russell’s theory of descriptions, 933–35

Saccheri, Gerolamo, 87

Saint Petersburg paradox, 747

Salem numbers, 828–29

sample average, 266

sample mean, 916

sample paths, 647, 649

sample space, 263–65

SAT, 582–83, 593, 596

satisfiable formulas, 582

satisfiable theories, 639

satisfying assignment, 582

scalar curvature, see curvature, scalar, 280, 488

scalar multiplication, 21, 285

scaling properties of partial differential equations, 477

scaling relations between critical exponents, 663

scattering theory, 287–88, 472

Schauder fixed point theorem, 696

schemes, 285, 367, 373, 377–79, 381

Schmidt, Friedrich Karl, 730–32

Schoenberg, Arnold, 940–41

Schottky problem, 418

Schrödinger equation, 216, 285–88, 456, 459, 472, 478, 514, 526, 540, 830

Schramm-Loewner evolution, see stochastic Loewner evolution

Schubert calculus, 62

Schweikart, F. K., 88

“Scottish Book, The” of Banach, 810

search engines, 30, 876–77; ranking problem for, 876

search problems, 577–78, 580–81

second derivative, 34

second largest eigenvalue, 198, 572

second moment method, 573

section of a bundle, 393

seed of a pseudorandom generator, 600

Seiberg-Witten invariants, see invariants, Seiberg-Witten

Seifert-van Kampen theorem, 437, 441

Selberg, Atle, 338, 341, 348

Selberg’s upper bound sieve, see sieves

self-adjoint matrices, see matrices, self-adjoint

self-adjoint operators, see operators, self-adjoint

self-avoiding random walk, 63, 70

self-reference, 701

self-similarity, 183, 502, 509

semi-parametric approach to statistical models, 925–26

semialgebraic sets, 364, 643–44

semidirect product, 24

sensitive dependence on initial conditions, 495–96, 501–2

sentences, 636–37, 641, 643

Serre, Jean-Pierre, 692, 732, 974, 1000, 1001

set of measure zero, 183, 247, 628, 686, 796

set systems, 568–69

set theory, 6, 9–10, 127–28, 143, 145–46, 314, 615–34, 776, 779; naive, 145

sexagesimal place-value system, 77–79

shadow price, 289

Shannon, Claude, 770, 812, 879, 881

Shannon wavelet, 859

Shannon’s theorem, 881–83

shape of a drum, 219, 837

Shelah, Saharon, 627, 630, 632–34, 646

shift operator, 239, 294, 520

Shimura varieties, 331, 419

Shimura-Taniyama-Weil conjecture, 69, 692

shock formation, 237

shock waves, 481, 775, 809, 818

Shor, Peter, 204, 271

shortest path, 310

Shuja, Abu Kamil, 133

Siegel, Carl, 337, 340

Siegel zeros, 340, 346, 681

SierpiImageski, Waclaw, 627, 801–2

SierpiImageski’s carpet, 801

sieves, 345–46; Brun, 345; combinatorial, 345; number field, 355; of Eratosthenes, 334, 345; Selberg’s upper bound, 346

sigma-algebra, 247

sigma models, 529, 532

signature of a permutation, 260

signature of a quadratic form, 268

similar matrices, see matrices, similar

simple connectedness, 38, 177, 309, 403, 714

simple groups, see groups, simple

simple harmonic oscillators, 524–27

simplex, 52, 162, 676–77

simplex algorithm, 288–90, 613

simply connected manifolds, see manifolds, simply connected

simulated annealing, 834

simultaneous linear equations, 22, 48, 102

sine function, see trigonometric functions

Singer, Isadore, 683

singular cardinal hypothesis, 630, 633

singular cardinals, see cardinals, singular

singular value decomposition, 608

singularities, 258, 281, 367–69, 415, 476; of an algebraic variety, 723

SIRS model, 845

six-exponentials theorem, 223

skein relation, 225–27

skew-Hermitian matrices, see matrices, skew-Hermitian

Skewes, Stanley, 804

Skolem, Thoralf, 622, 806–7

slack variables, 870

Sloane’s database, 992, 997

Smale, Stephen, 404, 714

smooth functions, 185

smooth manifolds, see manifolds, smooth

smooth numbers, 346, 354–56

smooth solutions, 195–96

smooth structures on manifolds, 397–99, 404, 407

Sobolev embedding theorem, 212, 449

Sobolev inequality, 705–6

Sobolev spaces, 211

social equilibrium, 900–901

solitons, 235–38

Solovay, Robert, 627, 629, 632

solubility by radicals, 102, 213

soluble groups, see groups, solvable

solvable groups, see groups, solvable

solving equations, 48–52

Sophie Germain primes, 892

soundness, 637; of a proof system, 592

space complexity of an algorithm, 114–15

space groups, 828

space-filling curve, 787

spacelike hypersurface, 468–69

spacelike vector, 43, 484, 487

spanning set, 22

spanning tree, 245

special functions, 290–93

special linear groups, 41, 230–31, 429, 688

special orthogonal groups, 39, 230, 425–26, 429

special relativity, see relativity, special

special unitary groups, 277

species, 150

spectral gap, 198

spectral radius formula, 518

spectral theorem, 217, 240, 295, 511–13, 519, 689

spectroscopy, 832

spectrum, 294–95, 472, 512; of a graph, 571

Sperner’s theorem, 64, 568

sphere, 53, 208, 215, 244, 282, 390, 400, 403, 670, 714, 728–29, 734; n-dimensional, 386

sphere packing, 58–60

spherical geometry, 40–41, 90, 92, 283, 401

spherical harmonics, 295–97

spherical Radon transform, 297

spherical structure, 401–2

spin configuration, 666

split-stepping, 237

splitting field, 213, 709

splitting law, 319, 325

splitting of a prime, 319, 322–23, 325–26, 330

spontaneous magnetization, 667

sporadic examples, 53

sporadic simple groups, 252, 688

spread, 150

square-integrable function, 511

square roots, 80–81, 327; of minus one, 56; of two, 30, 56, 78, 150, 222, 315–16, 710–11

squared error, 918

stability: of Minkowski space, 490–91; of orbits, 495; of the solar system, 728, 786, 815

stabilizer, 421, 442, 559

stable letter, 437–38

stacks, 367

standard deviation, 265–66

state-field correspondence, 544

states, 860; of physical systems, 513, 540; of a quantum computer, 269–70; on a von Neumann algebra, 517

statistical arbitrage, 916

statistical models, 922

statistics, 917–18

Stein’s paradox, 918–20

Steiner triple systems, 173

Steinitz, Ernst, 82, 105

Steinitz’s exchange lemma, see exchange axiom

Stevin, Simon, 80–82, 738

Stirling’s formula, 214

stochastic differential equations, 461, 654–55, 838

stochastic integrals, 651–52, 655

stochastic Loewner evolution, 655, 664–65

stochastic matrices, see matrices, stochastic

stock market crashes, 913

Stokes’s theorem, 179–80

Stone-Imageech compactification, see compactification, Stone-Imageech

stopping time, 653

Strassen, Volker, 66, 353

stress-energy-momentum tensor, 485–86

string theory, 164, 528–29, 538–41

strong cosmic censorship conjecture, 492

strong Fermat congruence, 351–52

strong law of large numbers, 266, 677, 815

strong Markov process, 653, 655

structural stability, 497

Sturm-Liouville equation, 291

Sturm-Liouville theory, 766

subrepresentations, 515

subroutines, 579

subset sum problem, 583

subspace topology, 302

substructures, 23

successive approximation, 31

successor function, 111, 146, 258

successor ordinal, 618

Suite for Piano (Schoenberg), 941

Sullivan, Dennis, 394, 510

Summa (Luca Pacioli), 99

sumsets, 569, 715, 718

super-attracting fixed point, 499

supercompact cardinals, see cardinals, supercompact superposition: in quantum mechanics, 269–72; principle of, 457–58

supremum norm, see L-norm

surfaces, 45, 53–54

surgeries, 281, 400; on links, 403

surjection, 11, 642

survival function in medical statistics, 923–24

Suslin, Mikhail, 628, 632

Suslin’s hypothesis, 624, 627, 632–33

Swinnerton-Dyer, Peter, 685

Sylvester, James Joseph, 103, 768–69

Sylvester’s law of inertia, 768

symbol of a Toeplitz operator, 521

symbols of PDEs, see partial differential equations, symbols of

symmetric groups, 234, 260, 422, 424, 561, 688, 709–10

symmetric polynomials, 329–30

symmetric relations, 12

symmetric space, 713

symmetry, 19, 52, 59–61, 204, 229, 273

symmetry groups, 39, 484

symmetry reductions, 480

symplectic geometry, 297–301, 531

symplectic groups, 230, 688

symplectic manifolds, see manifolds, symplectic

symplectic space: linear, 297, 300

syntonic comma, 937

Szemerédi’s regularity lemma, 571

Szemerédi’s theorem, 570

Szemerédi-Trotter theorem, 570

tableau, 289

tangent bundle, 313, 393

tangent space, 46

tangent vector, 176, 180

Tarski, Alfred, 627, 640–41, 643, 645, 813–14

Tauberian theorems, 803

tautology, 592

Taylor, Brook, 119, 745, 946

Taylor, Richard, 229, 252, 692–93

Taylor series, 38, 119, 122, 124, 200, 205, 282, 304, 541, 745

T-duality, 532–33, 537–38

Teichmüller spaces, 413–14, 416–18

Tennenbaum, Stanley, 627, 632

tensor categories, 275

tensor products, 272, 274–75, 301

ternary Goldbach problem, see Goldbach’s conjecture, ternary

tessellation, 42, 208

test functions, 185–86, 195

Thales of Miletus, 130

theorema aureum, 718

theorems, 73, 117, 130, 700

theoretical computer science, 7, 575–604

Théorie Analytique de la Chaleur (Fourier), 755

Théorie Analytique des Probabilités (Laplace), 753

theories, formal, 636–46

Theory of Linear Operations (Banach), 810

thermodynamic limit, 667

theta series, 268

Thompson, John, 60, 785

three-body problem, 51, 495–96, 726–28; restricted, 495, 728

three-dimensional manifolds, see manifolds, three-dimensional

Thurston, William, 388, 402–3, 461, 714

Thurston’s geometrization conjecture, see geometrization conjecture

timelike vector, 43, 484, 487

Tits, Jacques, 162

Toeplitz index theorem, 521

Toeplitz operators, see operators, Toeplitz

tomography problem, 307

topological group theory, 441–43

topological manifolds, see manifolds, topological

topological methods in combinatorics, 572

topological spaces, 182, 221, 227, 301–3, 309, 633

topological twisting, 530–31

Torricelli, Evangelista, 135

torus, 26, 45, 53, 208–9, 300, 309, 387–91, 530–33, 536–38, 711–13

total space, 392

totally disconnected set, 504

Tower of Hanoi, 113

trace, 515

trace-class operators, see operators, trace-class

Traité de Dynamique (d’Alembert), 750

transcendence of e, see e, transcendence of

transcendental numbers, 71–72, 81, 222–23, 241, 262, 616, 766, 773

transfinite numbers, 258, 616–19, 778–79

transition functions, 45, 282–83, 300, 396–98

transition matrices, 198

transitive actions, 421

transitive closure, 624

transitive relations, 12

translation invariance, 253, 457

transmission control protocol (TCP) of the Internet, 868

traveling salesman problem (TSP), 567, 583, 872–75

Treatise of Fluxions, A (Maclaurin), 121

tree, 442, 846

trefoil knot, 225–26, 979

trial division, 349–50, 355

triangle inequality, 248, 253, 268, 705, 790

triangulation, 54

trichotomy, law of, 127

trigonometric functions, 204, 220, 262, 295–96, 307–9

trigonometric polynomials, 212, 296, 451

trimmed mean, 916

Trotter product formula, 237

Turán’s theorem, 566

turbo codes, 886

turbulence, 815

Turing, Alan, 50, 113, 219, 358, 577, 638, 701, 707–8, 818, 821–22

Turing machines, 113, 576–78, 818

twelve-tone music, 940

twin prime conjecture, 362, 715, 804; asymptotic version, 343

twisted Chevalley groups, 688

two-dimensional arithmetic progression, 718

two-soliton interaction, 235

Tychonoff’s theorem, 168

types: Russell’s theory of, 147–48

Ulam, Stanislaw, 237, 359, 361, 568–69, 628, 958

umbrella problem, 561

unavoidable configurations, 697

uncertainty principle, see Heisenberg uncertainty principle

uncountable cardinals, see cardinals, uncountable

uncountable sets, 71, 146, 170–72, 183, 223, 247, 616–18, 622, 626–29, 632, 703, 806

undecidability, 622–25, 628–29, 633, 638–39; of first-order logic, 821

underdetermined system of equations, 459

uniform approximation, 253

uniform convergence, see convergence, uniform

uniform distribution, 263–64, 266, 674

uniform family of circuits, 585

uniformization theorem, 209, 281, 283, 416, 460, 728–29, 786

unipotent matrices, see matrices, unipotent

unique factorization, 221, 254–55, 285, 318, 320–25, 327, 692, 719

uniqueness of solutions, 48, 510

unit ball, 189, 671, 684, 693

unit in a ring, 318–19

unitary groups, 230

unitary maps, 211, 240, 270

unitary matrices, see matrices, unitary

unitary operators, see operators, unitary

unitary representations, see representations, unitary

universal covers, 309–10, 441–42

universal family of marked elliptic curves, 414

universal properties, 166, 301, 433–34, 436–37

universal set, 249

universality, 650, 657–59, 663–66, 669; of the Mandelbrot set, 508–9

universe of all sets, 314, 619–22, 625

unknot, 225–26, 403, 435

unlink, 225–26

upper-triangular matrices, see matrices, upper-triangular

vacuum Einstein equations, see Einstein equations, vacuum

vacuum state, 542

van der Waerden, Bartel, 104–5, 568

van der Waerden’s theorem, 568, 570

vanilla options, 914

van Ceulen, Ludolph, 109

variables, 15, 635

variance, 265–67

varieties, 272, 285, 313, 366, 376–80, 722–23; Abelian, 190, 418; abstract algebraic, 731; affine, 313; exponential, 644; function field of, 723; irreducible, 376; projective, 313; rational, 374

vector bundles, 176–77, 227, 313, 392–94; trivial, 313, 392

vector fields, 180, 393, 486

vector spaces, 21–22, 27–28, 30, 33, 52, 57, 103, 105, 172, 219, 239, 244–45, 253–54, 275–76, 278–79, 284–85, 294, 314, 419–25; basis of, 21–22, 28, 30, 223; dimension of, 22; direct sum of, 24; infinite dimensional, 22, 29

vertex operator algebra, 60, 541, 544–49

Viète, François, 99, 136, 737–38

Vinogradov, Ivan, 343

Vinogradov’s three-primes theorem, 715–16

Virasoro algebra, 544

Vitali, Giuseppe, 628, 684

Vitali covering lemma, 455

Vizing’s theorem, 565

volatility of a share price, 911–14

volume, 57, 158, 174, 183, 672, 679, 790; in n dimensions, 671

von Neumann, John, 148, 153, 512–13, 515–16, 817–19, 821

von Neumann algebras, 313, 515–17

von Neumann’s ergodic theorem, 512, 689–91

Voronoi diagram, 829

Voronoi surface, 842

Wallis, John, 87, 192

Wardrop equilibria, 865–66

Waring, Edward, 750–51, 804

Waring’s problem, 715, 717, 751, 803–4

wave equation, 35, 235–36, 456–57, 460, 466, 468, 478, 490

wave function, 216, 286

wavelets, 313–14, 848–62; Battle-Lemarié, 854; interval, 855; Mexican hat, 855; Meyer, 854; multiwavelets, 855

weak convergence, see convergence, weak

weak cosmic censorship conjecture, 492

weak law of large numbers, 266, 746

weak solutions to PDEs, 195–96, 313, 476

weakly compact cardinals, see cardinals, weakly compact

Weber, Heinrich, 241, 776

wedge product, 179

Weierstrass, Karl, 92, 124–29, 143–44, 476, 758, 770–71, 833

Weierstrass approximation theorem, 253, 452, 771

Weierstrass function, 833

Weierstrass P-function, 724

Weierstrass product expansion of the gamma function, 214

weight enumerators, 552–53

weighted AM-GM inequality, 704

Weil, André, 337, 347, 713, 819–21, 823, 966

Weil conjectures, 729–32, 820

Weil numbers, 331, 347

Weil’s theorem, 381–82

well-ordered set, 258, 617, 619, 624, 626

well-ordering principle, 108, 147, 158, 619, 621

well-posed problems, 468–69, 473

Well-Tempered Clavier (Bach), 938

Westzynthius, Erik, 66

Weyl, Hermann, 147–49, 151, 490, 521, 788, 805–6

Weyl curvature, see curvature, Weyl

Weyl formula, 219

Weyl group, 233–34

Whitehead link, 225

Whitney, Hassler, 244, 405

Whitney trick, 405

Wick rotation, 529

Wiener, Norbert, 648, 811–12

Wiener-Hopf equations, 812

Wiles, Andrew, 69, 229, 252, 359, 380, 381, 692, 693

Wilson’s theorem, 350, 751–52

winding numbers, 386, 410, 521, 532, 683

winning strategy, 159, 630–31

Witten, Edward, 404, 539

Woodin, Hugh, 141, 630, 632, 634

Woodin cardinals, see cardinals, Woodin

word hyperbolic groups, 446

word metrics, 443

word problems, 435–36, 440, 445–46; for groups, 708

world lines, 484; length of, 485

World Wide Web, 875

worldsheets, 529–40-41

worst-case complexity, 578

x-ray transform, 307

Yang-Baxter equations, 161

Yang-Mills equations, 490

Yau, Shing-Tung, 163

Yoneda lemma, 417

Young tableaux, 561, 995

Young’s inequality, 213, 451

Zariski topology, 303

Zelmanov, Efim, 438

zeolites, 834

Zermelo, Ernst, 128, 145, 147–48, 619–20, 780

Zermelo-Fraenkel set theory, 619

Zermelo-Russell paradox, 145

zero, 17, 79

zero divisors, 105, 276, 278

zero-one law, 646

zero-knowledge proof systems, 597–98

zeros of the Riemann zeta function, 336–38, 344, 357–58, 715

zeta functions, 284

ZF axioms, 128, 148, 314, 624

ZFC axioms, 314, 619–29, 634, 702

Zhu Shijie, 741

Zorn’s lemma, 158