The Dickman function, denoted usually as \(\rho(u)\), is a special mathematical function that arises in number theory, particularly in the study of the distribution of prime numbers and in analytic number theory. It is defined for \(u \geq 0\) and can be expressed using the following piecewise definition: 1. For \(0 \leq u < 1\): \[ \rho(u) = 1 \] 2.
The term "Einstein function" can refer to several concepts related to physicist Albert Einstein, depending on the context. However, it is most commonly associated with the **Einstein solid model**, a concept in statistical mechanics. ### Einstein Solid Model In this model, a solid is modeled as a collection of quantum harmonic oscillators. The basic idea is that each atom in the solid can vibrate in three dimensions, and these vibrations can be quantified in terms of energy quanta.
The Heaviside step function, often denoted as \( H(t) \) or \( u(t) \), is a piecewise function that plays a significant role in various branches of mathematics and engineering, particularly in control theory and signal processing.
It seems like you might be referring to "hyperbolic functions." Hyperbolic functions are analogs of the ordinary trigonometric functions but for a hyperbola rather than a circle. The primary hyperbolic functions are: 1. **Hyperbolic Sine** (\(\sinh\)): \[ \sinh(x) = \frac{e^x - e^{-x}}{2} \] 2.
The Incomplete Bessel K function and the generalized incomplete gamma function are specialized mathematical functions that arise in various fields including physics, engineering, and statistics. Let's break them down individually. ### Incomplete Bessel K Function The Incomplete Bessel K function, often denoted as \( K_\nu(x, a) \), is a variant of the modified Bessel function of the second kind, \( K_\nu(x) \).
The Incomplete Fermi-Dirac integral is a mathematical function that arises in the study of quantum statistical mechanics, particularly in connection with the behavior of fermions (particles that follow Fermi-Dirac statistics, such as electrons). This integral is particularly useful for systems at finite temperatures and is often involved in calculations related to electronic properties in materials, such as semiconductors and metals.
The incomplete polylogarithm is a generalization of the polylogarithm function, which is defined as: \[ \text{Li}_s(z) = \sum_{n=1}^{\infty} \frac{z^n}{n^s} \] for complex numbers \( z \) and \( s \). The series converges for \( |z| < 1 \), and can be analytically continued beyond this radius of convergence.
The inverse tangent integral typically refers to the integral defined by the function: \[ \int \frac{1}{1+x^2} \, dx = \tan^{-1}(x) + C \] where \( \tan^{-1}(x) \), also known as the arctangent function, is the inverse of the tangent function. The integral evaluates to the arctangent of \( x \), plus a constant of integration \( C \).
Kummer's function, commonly denoted as \( M(a, b, z) \), is a special function that arises in the context of solving differential equations, particularly the Kummer's differential equation. This function is also known as the confluent hypergeometric function.
The Legendre chi function, often denoted as \( \chi(n) \), is a number-theoretic function that is related to the Legendre symbol, which is a function used to determine whether an integer is a quadratic residue modulo a prime.
Silopi is a district located in Şırnak Province in southeastern Turkey, and it is known for its deposits of asphaltite, a naturally occurring solid hydrocarbon. Asphaltite is a type of asphalt that has a higher carbon content than traditional asphalt and is used in various applications, including road construction, roofing, and as a fuel source. The Silopi asphaltite mine refers to the mining operations in this region, where asphaltite is extracted for commercial use.
The term "logit" refers to a specific function used in statistics and econometrics, primarily in the context of logistic regression and other generalized linear models. The logit function is defined as the natural logarithm of the odds of an event occurring versus it not occurring.
The Lommel function is a special function that arises in the field of applied mathematics and mathematical physics, particularly in the context of wave propagation and similar problems. It is often associated with solutions to certain types of differential equations, such as those that appear in the study of cylindrical waves or in the analysis of diffraction patterns.
The Neville theta functions, often referred to in the context of mathematical analysis and theory, are a set of functions that arise in various areas such as number theory, representation theory, and the theory of modular forms. Specifically, the most common use is in the context of theta functions associated with even positive definite quadratic forms. In general, theta functions are important in mathematical analysis and find applications in statistical mechanics, combinatorics, and algebraic geometry.
The Beta angle, often denoted as β, is a term used in various fields, including astronomy, planetary science, and robotics, among others. Here are a few contexts in which the term might be relevant: 1. **Astronomy**: In the context of celestial mechanics, the Beta angle can refer to the angle between the plane of an object's orbit and a reference plane, such as the equatorial plane of the body it is orbiting.
The oblate spheroidal wave functions (OSWF) are a special class of functions that arise in the solution of certain types of differential equations, particularly in problems involving wave propagation in systems that exhibit axial symmetry. They are closely related to the solutions of the spheroidal wave equation, which is a generalization of the well-known spherical wave equation.
The parabolic cylinder functions, often denoted as \( U_n(x) \) and \( V_n(x) \), are special functions that arise in various applications, particularly in mathematical physics and solutions to certain differential equations. They are solutions to the parabolic cylinder differential equation, which is given by: \[ \frac{d^2 y}{dx^2} - \frac{1}{4} x^2 y = 0.
The Pochhammer contour is a specific type of contour used in complex analysis, particularly in the context of integrals involving certain types of functions or singularities. The contour is named after the mathematician Leo Pochhammer. The Pochhammer contour consists of a path in the complex plane that typically encloses one or more branch points, where a function may be multi-valued, such as logarithms or fractional powers.
Prolate spheroidal wave functions (PSWFs) are a set of mathematical functions that arise in various fields such as physics and engineering, particularly in the context of solving certain types of differential equations and in wave propagation problems. They are particularly useful in problems that exhibit some form of spherical symmetry or where boundary conditions are imposed on elliptical domains.
The rectangular function, often referred to as the "rect function," is a mathematical function that is commonly used in signal processing, communications, and other fields. It is defined as a piecewise function that takes the value 1 (or another constant value) over a specified interval and 0 elsewhere.

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