Graph theory is a rich area of mathematics with many interesting unsolved problems. Here are some notable ones: 1. **Graph Isomorphism Problem**: This problem asks whether two finite graphs are isomorphic, meaning they have the same structure regardless of the labels of their vertices. While there are polynomial-time algorithms for certain classes of graphs, a general polynomial-time solution for all graphs remains elusive.
Random graphs are mathematical structures used to model and analyze networks where the connections between nodes (vertices) are established randomly according to specific probabilistic rules. They are particularly useful in the study of complex networks, social networks, biological networks, and many other systems where the relationships between entities can be represented as graphs. ### Key Concepts in Random Graphs: 1. **Graph Definition**: A graph consists of nodes (or vertices) and edges (connections between pairs of nodes).
Graphs are mathematical structures used to model pairwise relationships between objects. They consist of vertices (or nodes) and edges (connections between the vertices). Graphs can be used to represent various systems in numerous fields, including computer science, social science, biology, and transportation. ### Key Terminology: 1. **Vertices (or Nodes)**: The fundamental units or points of the graph. They can represent entities such as people, cities, or any discrete items.
Graph theory is a branch of mathematics that studies graphs, which are mathematical structures used to model pairwise relationships between objects. In graph theory, the objects can be represented in various ways, but the fundamental components include: 1. **Vertices (Nodes)**: These are the fundamental units of a graph that represent the entities or objects. For example, in a social network, vertices could represent people. 2. **Edges (Links)**: These are the connections between pairs of vertices.
Graph operations refer to various manipulations and processes that can be performed on graphs, which are mathematical structures used to model pairwise relationships between objects. A graph consists of vertices (or nodes) and edges (connections between the vertices). Graph operations can help analyze, modify, or derive new graphs from existing ones. Here are some common types of graph operations: 1. **Graph Creation**: - **Adding Vertices**: Introducing new vertices to an existing graph.
Graph minor theory is a significant area of research within graph theory that deals with the concept of "minors." A graph \( H \) is said to be a minor of a graph \( G \) if \( H \) can be formed from \( G \) by a series of operations that include: 1. **Deleting vertices**: Removing a vertex and its associated edges. 2. **Deleting edges**: Removing edges between vertices.

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