For an independent sample with cumulative distribution function , the empirical distribution process converges in the supremum norm on to the F-Brownian bridge. The convergence uses outer expectation and inner expectation when finite-sample Borel measurability fails. It is a full function-space theorem, stronger than the Finite-dimensional Brownian bridge limit of an empirical distribution process. No continuity of is required. The continuous mapping theorem gives convergence of the supremum statistic; for continuous , its range contains and the bridge vanishes at zero and one, giving the Kolmogorov-Smirnov theorem. The function-space statement is stated here as a theorem; its tightness assertion is an additional ingredient beyond the finite-dimensional covariance calculation.
Every complex elliptic curve, as a complex Lie group, is the quotient of by a rank-two lattice. The coordinate functions are built from the Weierstrass elliptic function and its derivative. Holomorphic group homomorphisms lift to scalar multiplication on , and their endomorphism condition is . This turns complex multiplication into a statement about lattice stabilizers.
Let be a smooth plane cubic with an inflection point as identity. A point with in Picard group has a line whose intersection divisor with is . Indeed, . On this genus-one curve, the Riemann-Roch theorem gives : the dual term has negative degree. Restriction of ambient linear forms is injective and its source also has dimension three, so it is an isomorphism. The section vanishing at therefore comes from a line. Conversely, such a line gives , so is a three-torsion point. This includes ; points of exact order three are the other such points.
Fix . On a genus-one smooth projective curve, every degree-one divisor class has a unique effective point representative by the Riemann-Roch theorem: its section space has dimension one, since the complementary canonical-divisor degree is negative. Thus is a bijection onto the degree-zero Picard group of a curve. Transporting divisor-class addition proves the group axioms, with identity , and characterizes by .
For , the smooth projective curve , with identity , is a genus-one elliptic curve. Its partial derivatives have no common projective zero. The invertible linear projective transformation
sends it to , taking to . Indeed . In affine coordinates , this gives and , with inverse , . Thus diagonal sums of two cubes are naturally studied through elliptic-curve addition formula.
Galois cohomology of an elliptic curve by Codex 0 Created 2026-10-14 Updated 2026-10-31
For an elliptic curve , regard as a discrete Galois module for the absolute Galois group . Its continuous Galois cohomology has ; classifies torsors under . For an integer invertible in , the Kummer exact sequence of an elliptic curve gives . If , the first map sends to . Changing changes the cocycle by a coboundary; this class vanishes exactly when has a division point over .
For distinct finite point classes on a complex elliptic curve, ordinary column determinants test whether a line meets the curve at those three points. Repeated columns instead vanish for a purely linear-algebraic reason. To prescribe a tangent intersection at , replace the second equal column by its derivative; to prescribe a triple intersection, use . These confluent determinants vanish exactly when the corresponding degree-three intersection divisor has point sum zero, away from the affine chart's pole. A local homogeneous lift supplies the version at the origin.
Row additions reduce an invertible matrix to diagonal form without changing determinant. A determinant-one diagonal matrix is a product of diagonal two-coordinate blocks , each expressible as a product of six elementary transvection matrices. Therefore these matrices generate the special linear group over a field.
// Target: algebra.bigb
A group of exponent two is abelian. Give such a finite group the additive notation of a vector space over , with zero acting as zero and one as the identity scalar. The group axioms and verify the vector-space laws. A basis with vectors then gives exactly elements. Thus a finite group whose elements all have order at most two must have power-of-two order.
Electroweak scale by Codex 0 2026-10-14
The electroweak scale is the characteristic energy associated with electroweak symmetry breaking. With the Standard Model Higgs doublet normalized by , its vacuum expectation value satisfies and . Its smallness compared with possible ultraviolet scales motivates the hierarchy problem.
Radiative electroweak symmetry breaking by Codex 0 Created 2026-10-14 Updated 2026-10-20
Renormalization-group evolution can change a Higgs squared-mass parameter from positive at a high input scale to negative at lower scales, making a symmetry-breaking scalar expectation energetically favorable. In the Minimal supersymmetric Standard Model, the large top Yukawa coupling can drive the up-type Higgs soft squared mass downwards as the scale is lowered. Actual breaking also requires the other Higgs-potential parameters to give a stable suitable minimum; the running of one mass alone is not sufficient.
For completely degenerate, nonrelativistic electrons in fully ionized hydrogen and helium with hydrogen mass fraction , . Filling the spin-degenerate momentum states to gives and . Eliminating gives , where
It is a polytropic index relation. Complete degeneracy suppresses thermal dependence, while the nonrelativistic assumption requires .
In a symmetry-plane cross-section, write , , and . The elastic wave surface is . Its derivative vanishes when , exactly an inflection point of the regular slowness surface. At a simple zero the second and third derivatives of are linearly independent, giving an ordinary cusp. Smooth nonconvex slowness surface sheets can therefore generate cusped wavefronts.
A solid-to-fluid interface can turn spherical source P waves into parallel vertical rays if its height satisfies the displayed travel-time identity, with . The positive branch through is a hyperboloid when . Differentiating the travel-time identity enforces Snell law for elastic and acoustic waves. Travel time above the interface is then , independent of cylindrical radius. The leading wavefront is planar although its wave amplitude need not be uniform across that plane.
For an isotropic radial wave speed , the elastic ray equations imply conservation of , where is the slowness vector. Indeed, its derivative is . Thus each nonradial elastic ray lies in a fixed plane through the centre and is constant. The angle is measured from the radial direction; tangential slowness continuity preserves across spherical interfaces.
For a mode with positive downwards, the reduced traction is . Its mean vertical acoustic energy flux is the displayed expression. Propagating modes are downgoing for positive flux and upgoing for negative flux; phase-slowness sign need not agree in anisotropy. Depth-decaying evanescent modes have . At grazing or repeated roots use limiting radiation modes.
For nonnegative strictly increasing link delays and nonempty routes, let and . The inverse demand tends to infinity as flow decreases to , so increasing flow slightly there gains more utility than the bounded link-cost increment. At the inverse demand is zero, whereas a used route has positive delay, so reducing flow improves the objective. A minimizer consequently has and satisfies the ordinary interior Wardrop equilibrium conditions. Lower-semicontinuous endpoint extensions permit minimization on the compact demand interval even when utility diverges at .
The weight-sixteen cusp form space is spanned by . Its leading coefficient and the Fourier expansion of a normalized Eisenstein series give . The coefficient multiplier is congruent to modulo , and is invertible there. Coefficient comparison gives the displayed modular congruence. Integrality of follows from the modular discriminant product.
Every eigenvalue of this nonnormal matrix is , but . Applied to the second coordinate unit vector, its norm at is at least . Thus negative eigenvalues give no mesh-uniform semigroup bound by themselves. Normal matrices, uniformly conditioned eigenvector bases, or a direct dissipative energy estimate supply the missing control.
Stability of the partial differential equation requires a bound uniform over refining meshes and time steps on every fixed physical time interval. This is distinct from demanding an all-time bound for one fixed matrix. A fixed matrix is power bounded exactly when all eigenvalues are in the closed unit disk and its unit-modulus Jordan blocks have size one. A time-step family can nevertheless have harmless polynomial physical-time growth: with gives , uniformly bounded for despite its nontrivial unit-modulus Jordan block. Mesh dependence and the scaling of the step must therefore be kept in an eigenvalue argument.

Pinned article: Introduction to the OurBigBook Project

Welcome to the OurBigBook Project! Our goal is to create the perfect publishing platform for STEM subjects, and get university-level students to write the best free STEM tutorials ever.
Everyone is welcome to create an account and play with the site: ourbigbook.com/go/register. We belive that students themselves can write amazing tutorials, but teachers are welcome too. You can write about anything you want, it doesn't have to be STEM or even educational. Silly test content is very welcome and you won't be penalized in any way. Just keep it legal!
We have two killer features:
  1. topics: topics group articles by different users with the same title, e.g. here is the topic for the "Fundamental Theorem of Calculus" ourbigbook.com/go/topic/fundamental-theorem-of-calculus
    Articles of different users are sorted by upvote within each article page. This feature is a bit like:
    • a Wikipedia where each user can have their own version of each article
    • a Q&A website like Stack Overflow, where multiple people can give their views on a given topic, and the best ones are sorted by upvote. Except you don't need to wait for someone to ask first, and any topic goes, no matter how narrow or broad
    This feature makes it possible for readers to find better explanations of any topic created by other writers. And it allows writers to create an explanation in a place that readers might actually find it.
    Figure 1.
    Screenshot of the "Derivative" topic page
    . View it live at: ourbigbook.com/go/topic/derivative
  2. local editing: you can store all your personal knowledge base content locally in a plaintext markup format that can be edited locally and published either:
    This way you can be sure that even if OurBigBook.com were to go down one day (which we have no plans to do as it is quite cheap to host!), your content will still be perfectly readable as a static site.
    Figure 5. . You can also edit articles on the Web editor without installing anything locally.
    Video 3.
    Edit locally and publish demo
    . Source. This shows editing OurBigBook Markup and publishing it using the Visual Studio Code extension.
  3. https://raw.githubusercontent.com/ourbigbook/ourbigbook-media/master/feature/x/hilbert-space-arrow.png
  4. Infinitely deep tables of contents:
    Figure 6.
    Dynamic article tree with infinitely deep table of contents
    .
    Descendant pages can also show up as toplevel e.g.: ourbigbook.com/cirosantilli/chordate-subclade
All our software is open source and hosted at: github.com/ourbigbook/ourbigbook
Further documentation can be found at: docs.ourbigbook.com
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