The Cauchy–Euler operator, also known as the Cauchy–Euler differential operator, refers to a specific type of differential operator that is commonly used in the analysis of differential equations of the form: \[ a x^n \frac{d^n y}{dx^n} + a x^{n-1} \frac{d^{n-1} y}{dx^{n-1}} + \cdots + a_1 x \frac{dy}{dx
The Cramér–Wold theorem is a result in probability theory that provides a characterization of multivariate normal distributions. It states that a random vector follows a multivariate normal distribution if and only if every linear combination of its components is normally distributed. More formally, let \( X = (X_1, X_2, \ldots, X_n) \) be a random vector in \( \mathbb{R}^n \).
The Cohen–Hewitt factorization theorem is an important result in the field of functional analysis, particularly in the study of commutative Banach algebras and holomorphic functions. The theorem essentially deals with the factorization of elements in certain algebras, specifically those elements that have a suitable structure, such as being the spectrum of a compact space.
The Eberlein–Šmulian theorem is a result in functional analysis that characterizes weak*-compactness in the dual space of a Banach space. Specifically, it provides a criterion for when a subset of the dual space \( X^* \) (the space of continuous linear functionals on a Banach space \( X \)) is weak*-compact.
An enveloping von Neumann algebra is a concept from the field of functional analysis, specifically in the context of operator algebras. To understand this concept, we first need to clarify what a von Neumann algebra is. A **von Neumann algebra** is a *-subalgebra of bounded operators on a Hilbert space that is closed in the weak operator topology and contains the identity operator.
The Fifth-order Korteweg–De Vries (KdV) equation is a mathematical model that extends the classical KdV equation, which is used to describe shallow water waves and other dispersive wave phenomena.
Friedrichs's inequality is a fundamental result in the field of functional analysis and partial differential equations. It provides a way to control the norm of a function in a Sobolev space by the norm of its gradient. Specifically, it is often used in the context of Sobolev spaces \( W^{1,p} \) and \( L^p \) spaces.
Hadamard's method of descent, developed by the French mathematician Jacques Hadamard, is a technique used in the context of complex analysis and number theory, particularly for studying the growth and distribution of solutions to certain problems, such as Diophantine equations and modular forms. The method relies on the concept of reducing a problem in higher dimensions to a problem in lower dimensions (hence the term "descent").
A holomorphic curve is a mathematical concept from complex analysis and algebraic geometry. Specifically, it refers to a curve that is defined by holomorphic functions. Here’s a breakdown of what this means: 1. **Holomorphic Functions**: A function \( f: U \rightarrow \mathbb{C} \) is called holomorphic if it is complex differentiable at every point in an open subset \( U \) of the complex plane.
The term "infra-exponential" may not be widely recognized in most contexts, as it is not a standard term in mathematics, economics, or other fields. However, it appears to indicate a concept that could relate to functions or behaviors that grow or decay at rates slower than exponential functions.
Integration using parametric derivatives often involves evaluating integrals in the context of parametric equations. This approach is commonly employed in calculus, especially in the study of curves defined by parametric equations in two or three dimensions. ### What are Parametric Equations? Parametric equations express the coordinates of points on a curve as functions of one or more parameters.
The lower convex envelope, often referred to as the convex hull of a set of points, is a fundamental concept in computational geometry and optimization. It essentially represents the smallest convex shape that can encompass a given set of points or an entire function. For a set of points in a Euclidean space, the lower convex envelope is the boundary of the convex hull that lies below the given points.
The Mandelbox is a type of fractal, specifically a 3D fractal that is an extension of the Mandelbrot set. It was discovered by artist and mathematician Bert Wang. The Mandelbox fractal is generated using a combination of simple transformations and complex mathematical rules, primarily involving iterations of mathematical functions. The structure of the Mandelbox is notable for its intricate, self-similar shapes and the depth of detail that can be found within it, which can be zoomed into indefinitely.
Mixed boundary conditions refer to a type of boundary condition used in the context of partial differential equations (PDEs), where different types of conditions are applied to different parts of the boundary of the domain. Specifically, a mixed boundary condition can involve both Dirichlet and Neumann conditions, or other types of conditions, imposed on different sections of the boundary.
The Monodromy matrix arises in the context of differential equations, particularly in the study of linear differential equations or systems of linear differential equations. It provides valuable information about the behavior of solutions as they are analytically continued along paths in the complex plane. ### Key Concepts: 1. **Differential Equations**: Consider a linear ordinary differential equation (ODE) or a system of linear differential equations.
Motz's problem is a question in recreational mathematics named after mathematician John Motz. The problem typically asks whether it is possible to distribute a given number of objects (often identified in the context of combinatorial games or puzzles) in such a way that certain conditions or constraints are satisfied. One common formulation of Motz's problem involves partitioning a set of items or arranging them in configurations that follow specific rules, often leading to intriguing and complex patterns.
Jean Favard is a French mathematician known for his work in the field of analysis, particularly for his contributions to the theory of functions of several variables, including the Favard theorem related to set functions and measures. He has also made impacts in various areas of real analysis and topology.
The Pansu derivative is a concept from the field of geometric measure theory and analysis on metric spaces, particularly related to the study of Lipschitz maps and differentiability in the context of differentiable structures on metric spaces. It is named after Pierre Pansu, who introduced the idea while investigating the behavior of Lipschitz functions on certain types of spaces, especially in relation to their geometry.
The Sarason interpolation theorem is a result in complex analysis related to the theory of functional spaces, particularly in the context of the Hardy space \( H^2 \). It provides a criterion for the existence of an analytic function that interpolates a given sequence of points in the unit disk, subject to certain conditions.
The term "spectral component" can refer to different concepts depending on the context in which it is used—such as in physics, engineering, or signal processing. Generally, it refers to the individual frequency or wavelength components that make up a signal or a wave in the frequency domain.

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
Feel free to reach our to us for any help or suggestions: docs.ourbigbook.com/#contact