The Narasimhan-Seshadri theorem is a fundamental result in the theory of vector bundles over complex curves (or Riemann surfaces). It establishes a deep connection between the geometry of vector bundles and the representation theory of groups, particularly in the context of holomorphic vector bundles on Riemann surfaces and unitary representations of the fundamental group.
The Denjoy-Wolff theorem is a result in complex analysis, particularly in the field of iterated function systems and the study of holomorphic functions. It characterizes the dynamics of holomorphic self-maps of the unit disk, specifically focusing on the behavior of iterates of such functions.
The Double Limit Theorem, often referred to in the context of limits in calculus, relates to the properties and behavior of limits involving functions of two variables.
The Unique Homomorphic Extension Theorem is a result in the field of algebra, particularly concerning rings and homomorphisms. It typically states that if you have a ring \( R \) and a subring \( S \), along with a homomorphism defined on \( S \), then there exists a unique (in the case of certain conditions) homomorphic extension of this mapping up to the whole ring \( R \).
The Whitney extension theorem is a fundamental result in the field of analysis and differential geometry, concerning the extension of functions defined on a subset of a Euclidean space to the entire space while preserving certain properties.
In computational complexity theory, a theorem typically refers to a proven statement or result about the inherent difficulty of computational problems, particularly concerning the resources required (such as time or space) for their solution.
Extensive quantities are properties of a system that depend on the amount of material or the size of the system. In other words, they are additive properties that change when the system is divided into smaller parts. Extensive quantities are proportional to the size or extent of the system. Common examples of extensive quantities include: 1. **Mass** - The total amount of matter in a system. 2. **Volume** - The amount of three-dimensional space occupied by the system.
Lagrange's identity is a mathematical formula that relates the sums of squares of two sets of variables. It is often stated in the context of inner product spaces or in terms of quadratic forms.
The book unfortunately does not cover the history of quantum mechanics very, the author specifically says that this will not be covered, the focus is more on particles/forces. But there are still some mentions.
The Nexon Computer Museum is a museum located in Seongnam, South Korea, dedicated to the history and culture of computers and gaming. Opened in 2018, it is a part of Nexon, a well-known video game company, and aims to preserve and showcase the evolution of computer technology and gaming from the 20th century to the present day.
The time-independent Schrödinger equation is a variant of the Schrödinger equation defined as:
Equation 1.
Time-independent Schrodinger equation
.
So we see that for any Schrödinger equation, which is fully defined by the Hamiltonian , there is a corresponding time-independent Schrödinger equation, which is also uniquely defined by the same Hamiltonian.
The cool thing about the Time-independent Schrödinger equation is that we can always reduce solving the full Schrödinger equation to solving this slightly simpler time-independent version, as described at: Section "Solving the Schrodinger equation with the time-independent Schrödinger equation".
Because this method is fully general, and it simplifies the initial time-dependent problem to a time independent one, it is the approach that we will always take when solving the Schrodinger equation, see e.g. quantum harmonic oscillator.
The Poincaré–Bendixson theorem is a fundamental result in the field of dynamical systems, particularly concerning the behavior of continuous dynamical systems in two dimensions. It addresses the long-term behavior of trajectories in a planar (2-dimensional) system described by a set of ordinary differential equations.

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 2.
    You can publish local OurBigBook lightweight markup files to either https://OurBigBook.com or as a static website
    .
    Figure 3.
    Visual Studio Code extension installation
    .
    Figure 4.
    Visual Studio Code extension tree navigation
    .
    Figure 5.
    Web editor
    . 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.
    Video 4.
    OurBigBook Visual Studio Code extension editing and navigation demo
    . Source.
  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