The Hermitian adjoint (or conjugate transpose) of a matrix is a fundamental concept in linear algebra, particularly in the context of complex vector spaces. For a given matrix \( A \), its Hermitian adjoint (denoted as \( A^\dagger \) or \( A^* \)) is obtained by taking the transpose of the matrix and then taking the complex conjugate of each entry.
ECHAM is a numerical weather prediction model used for simulating and forecasting weather and climate. It is based on the equations of fluid dynamics and thermodynamics governing the atmosphere. Developed by the Max Planck Institute for Meteorology in Hamburg, Germany, ECHAM is part of the wider family of global climate models (GCMs) and is specifically designed for atmospheric research. The name "ECHAM" stands for "Eulerian Climate and High-Resolution Atmospheric Model.
Sz.-Nagy's dilation theorem is a result in operator theory, particularly in the study of contraction operators on Hilbert spaces. It provides a framework for understanding certain types of linear operators by representing them in a higher-dimensional space. The primary aim of the theorem is to "dilate" a given operator into a unitary operator, which preserves the properties of the original operator while allowing for a more thorough analysis.
The Poincaré–Lindstedt method is a mathematical technique used to analyze and approximate solutions to nonlinear differential equations, particularly in the context of perturbation theory. It is named after Henri Poincaré and Karl Lindstedt, who contributed to the development of methods for understanding the behavior of dynamical systems. ### Overview: The method is typically applied to study oscillatory or periodic solutions of differential equations that have small parameters, often referred to as perturbations.
A Jordan matrix, also known as a Jordan block, is a special type of square matrix that arises in linear algebra, particularly in the context of Jordan canonical form. A Jordan block is associated with an eigenvalue of a matrix and has a specific structure that reflects the algebraic and geometric multiplicities of that eigenvalue.
Orbital perturbations refer to the deviations or modifications in the motion of an orbiting body (such as a planet, satellite, or spacecraft) caused by various gravitational influences and non-gravitational factors. In a perfect two-body system, the orbits can be described by conic sections (ellipses, parabolas, or hyperbolas), but in the real universe, several factors can cause perturbations from these ideal trajectories.
Laplace's method is a technique used in asymptotic analysis to approximate integrals of the form \[ I_n = \int_{a}^{b} e^{n f(x)} g(x) \, dx \] as \( n \) becomes large, where \( f(x) \) is a smooth function and \( g(x) \) is another function that is reasonably well-behaved.
Balayage is a hair coloring technique that involves hand-painting highlights onto the hair to create a natural, sun-kissed effect. The term "balayage" is derived from the French word "balayer," which means "to sweep." This technique allows for a more blended and gradual transition of color, unlike traditional highlighting methods that use foils and tend to create a more uniform look.
Focaloid is a vocal synthesis software that allows users to create music using vocal tracks generated by a computer. It operates similarly to other vocal synthesis programs like Vocaloid, which utilizes voice banks recorded by human singers. Users can input melodies and lyrics, and the software synthesizes the singing voice, enabling the creation of songs even if the user doesn't have a vocalist on hand. Focaloid, specifically, may offer unique features regarding customization, voice manipulation, or the range of voice banks available.
Kellogg's theorem, in the context of topology and mathematical analysis, specifically deals with the behavior of continuous functions and the structure of spaces in relation to certain properties of sets. The theorem asserts that if a sequence of open sets in a topological space has certain convergence properties, then their limit behaves in a controlled manner.
The term "hundredth" generally refers to a position in a sequence or a fractional part. Here are some common contexts in which "hundredth" is used: 1. **Fractional/Decimal**: In terms of fractions, "hundredth" represents one part of a hundred, or \( \frac{1}{100} \). In decimal terms, it is expressed as 0.01.
Supersymmetric quantum field theory (SUSY QFT) is a theoretical framework that extends the principles of quantum field theory by incorporating the concept of supersymmetry. Supersymmetry is a proposed symmetry that relates particles of different spins, specifically, it suggests a relationship between bosons (particles with integer spin) and fermions (particles with half-integer spin).
The anomalous magnetic dipole moment refers to a deviation of a particle's magnetic moment from the prediction made by classical electrodynamics, which is primarily described by the Dirac equation for a spinning charged particle, like an electron. In classical theory, the magnetic moment of a charged particle is expected to be proportional to its spin and a factor of the charge-to-mass ratio.
The term "BF model" can refer to different concepts, depending on the context. Here are a few possibilities: 1. **Bachmann–Landau–Fuchs (BLF) Model**: In mathematics and physics, there are models that describe complex systems, but "BF model" could refer to specific models related to theories in quantum field theories or statistical mechanics.
Chern–Simons theory is a type of topological field theory in theoretical physics and mathematics that describes certain properties of three-dimensional manifolds. It is named after mathematicians Shiing-Shen Chern and Robert S. Simon, who developed the foundational concepts related to characteristic classes in the context of differential geometry.
The Cobordism Hypothesis is a concept in the field of higher category theory, particularly in the study of topological and geometric aspects of homotopy theory. It can be loosely described as a relationship between the notion of cobordism in topology and the structure of higher categorical objects.
Constraint algebra is a mathematical framework that focuses on the study and manipulation of constraints, which are conditions or limitations placed on variables in a mathematical model. Generally, it is used in optimization, database theory, artificial intelligence, and various fields of mathematics and computer science. ### Key Concepts in Constraint Algebra: 1. **Constraints**: Conditions that restrict the values that variables can take. For example, in a linear programming problem, constraints can specify that certain variables must be non-negative or must satisfy linear inequalities.
DeWitt notation is a mathematical shorthand used primarily in the field of theoretical physics, particularly in quantum field theory and general relativity. It was proposed by physicist Bryce DeWitt to simplify the representation of various mathematical expressions involving sums, integrals, and the treatment of indices. In DeWitt notation, the following conventions are typically used: 1. **Indices**: The indices associated with tensor components are often suppressed or simplified through the use of a compact notation.
Feynman parametrization is a mathematical technique used in quantum field theory and particle physics to simplify the evaluation of integrals that arise in loop calculations. These integrals often involve products of propagators, which can be difficult to handle directly. The Feynman parametrization helps to combine these propagators into a single integral form that is easier to evaluate.
Hamiltonian truncation is a method used in theoretical physics, particularly in the study of quantum field theories (QFTs) and in the context of many-body physics. It involves simplifying a complicated quantum system by truncating or approximating the Hamiltonian, which is the operator that describes the total energy of the system, including both kinetic and potential energy contributions. ### Key Concepts 1.

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