An Equiareal map, also known as an equal-area map, is a type of map projection that maintains the consistency of area proportions across the entire map. This means that regions on the map are represented in the same area ratio as they are on the Earth's surface. As a result, if two areas are equal in size on the map, they will also be equal in size in reality, regardless of their location.
A Kähler-Einstein metric is a special type of Riemannian metric that arises in differential geometry and algebraic geometry. It is associated with Kähler manifolds, which are a class of complex manifolds with a compatible symplectic structure. A Kähler manifold is a complex manifold \( (M, J) \) equipped with a Kähler metric \( g \), which is a Riemannian metric that is both Hermitian and symplectic.
The Equivariant Index Theorem is a significant result in mathematics that generalizes the classical index theorem in the context of equivariant topology, particularly in the presence of group actions. It relates the index of an elliptic differential operator on a manifold equipped with a group action to topological invariants associated with the manifold and the group.
Equivalent latitude is a concept used in atmospheric science and meteorology to describe the latitude corresponding to a particular atmospheric condition or property that is typically associated with a certain latitude in the atmosphere. It is often used in the context of phenomena such as the stratosphere, tropopause, or specific atmospheric trace gases. One common application of equivalent latitude is in the study of the ozone layer and the polar vortex.
The Filling Area Conjecture is a concept from the field of geometric topology, particularly in the study of three-dimensional manifolds. It concerns the relationship between the topological properties of a surface and its geometric properties, specifically focusing on the area of certain types of surfaces. The conjecture originates from the study of isotopy classes of simple curves on surfaces.
A **Finsler manifold** is a generalization of a Riemannian manifold that allows for the length of tangent vectors to be defined in a more flexible way. While Riemannian geometry is based on a positive-definite inner product that varies smoothly from point to point, Finsler geometry introduces a more general function, referred to as the **Finsler metric**, which defines the length of tangent vectors.
A G2-structure is a mathematical concept within the field of differential geometry, particularly in the study of special types of manifolds. More specifically, G2-structures are related to the notion of "exceptional" symmetries and are associated with the G2 group, which is one of the five exceptional Lie groups.
Gaussian curvature is a measure of the intrinsic curvature of a surface at a given point. It is defined as the product of two principal curvatures at that point, which are the maximum and minimum curvatures of the surface in two perpendicular directions.
A geodesic manifold is a type of manifold in differential geometry where the notion of distance and the concept of geodesics, which are the shortest paths between points, can be defined. More specifically, it often refers to a Riemannian manifold equipped with a Riemannian metric, allowing for the computation of distances and angles.
The Haefliger structure, often referred to in the context of differential geometry and topology, is a specific kind of manifold structure that arises in the study of pseudogroups and foliated spaces. It is named after André Haefliger, who contributed significantly to the classification of certain types of smooth structures on manifolds.
A Hitchin system is a mathematical structure that arises in the study of integrable systems, particularly in the context of differential geometry and algebraic geometry. It is named after Nigel Hitchin, who introduced these systems in the context of the theory of stable bundles and the geometry of moduli spaces. More specifically, a Hitchin system is typically defined on a compact Riemann surface and can be understood as a certain type of symplectic manifold.
Homological mirror symmetry (HMS) is a conjectural framework in mathematical physics and algebraic geometry that relates certain aspects of symplectic geometry and algebraic geometry. It emerges primarily from the work of Maxim Kontsevich in the late 1990s. The conjecture provides a deep relationship between the geometry of a space and the derived category of coherent sheaves on that space, particularly in the context of mirror symmetry—a phenomenon that originated in string theory.
An integral curve is a concept from differential equations and dynamical systems that refers to a curve in the phase space of a system along which the system evolves over time. More specifically, it represents the solutions to a differential equation for given initial conditions.
The Myers–Steenrod theorem is an important result in differential geometry, particularly in the study of Riemannian manifolds. It primarily deals with the structure of Riemannian manifolds that have certain properties related to curvature.
K-noid is a term that may refer to specific concepts or topics depending on the context, but it is not widely recognized in mainstream discourse or academic literature. However, it is possible that "K-noid" could pertain to a niche subject such as blockchain technology, programming, a concept in a game, or something else entirely.
Lie sphere geometry, also known as the geometry of spheres, is a branch of differential geometry that studies the projective properties of spheres in a higher-dimensional space. This geometric framework is named after the mathematician Sophus Lie, who contributed significantly to the understanding of transformations and symmetries in geometry.
Mean curvature is a geometric concept that arises in differential geometry, particularly in the study of surfaces. It measures the average curvature of a surface at a given point and is an important characteristic in the study of minimal surfaces and the geometry of manifolds. For a surface defined in three-dimensional space, the mean curvature \( H \) at a point is given by the average of the principal curvatures \( k_1 \) and \( k_2 \) at that point.
Mostow rigidity theorem is a fundamental result in the field of differential geometry, particularly in the study of hyperbolic geometry. It states that if two closed manifolds (or more generally, two complete Riemannian manifolds that are simply connected and have constant negative curvature) are isometric to each other, then they are also equivalent up to a unique way of deforming them.
The nonmetricity tensor is a mathematical object used in the context of a generalization of the theory of gravity, particularly in modifications of general relativity, such as in theories of metric-affine geometry. In differential geometry, the notion of nonmetricity is concerned with the way lengths and angles change under parallel transport. In the context of a connection on a manifold, the nonmetricity tensor is defined as the tensor that measures the failure of the connection to preserve the metric tensor during parallel transport.
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!
Intro to OurBigBook
. Source. We have two killer features:
- 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-calculusArticles 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/derivativeVideo 2. OurBigBook Web topics demo. Source. - 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.
- to OurBigBook.com to get awesome multi-user features like topics and likes
- as HTML files to a static website, which you can host yourself for free on many external providers like GitHub Pages, and remain in full control
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. - Infinitely deep tables of contents:
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





