# Network theory Network theory studies graphs whose vertices and edges carry attributes, analyzing connectivity, [[Centrality|centrality]], assortativity, flow, contagion, and resilience. Applications span social, biological, infrastructural, and informational networks, linking combinatorial optimization, [[Scale-free_network|scale-free]] structure, and dynamical processes on graphs. Its mathematical core is [[Graph_theory|graph theory]]. <!-- MICROSIMGEN:BEGIN v1.7 — generated by g08_place_microsims.py; three.js first (§15); do not hand-edit inside --> ## Microsims — three.js ### Network theory (three.js) <div class="microsim-player"> <iframe src="https://wikitube-3d-microsims.netlify.app/Network_theory.html" width="100%" height="620" frameborder="0" loading="lazy" sandbox="allow-scripts allow-same-origin" title="Network theory — three.js microsim"></iframe> </div> **Open it full-screen:** [Network_theory.html](https://wikitube-3d-microsims.netlify.app/Network_theory.html) · library `threejs` · route `microsim/threejs/` ### Related microsims Live sims on neighbouring articles — 6 of them inside this article's own Wikipedia link tree: - [[Agent-based_model]] *(in tree)* - [[Complex_system]] *(in tree)* - [[Emergence]] *(in tree)* - [[Feedback]] *(in tree)* - [[Phase_space]] *(in tree)* - [[Self-organization]] *(in tree)* *Sim hosted off-article; the article owns the reference, not the runtime (WIKI_RULES §10.4). Placed by `g08_place_microsims.py`.* <!-- MICROSIMGEN:END --> ## Reveal %%REVEAL:d3%% %%REVEAL:three%% --- *Concept aligned with [Wikipedia](https://en.wikipedia.org/wiki/Network_theory); adapted text, where present, is licensed [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0/).* ## Overview From [[Leonhard_Euler|Leonhard Euler]]'s bridges to the [[Small-world_network|small-world network]], the [[Random_graph|random graph]], the [[Bipartite_graph|bipartite]] and [[Directed_graph|directed graph]], and the recurring [[Network_motif|network motif]], the field turned structure into measurement — then [[Network_science|network science]] and [[Statistical_mechanics|statistical mechanics]] turned measurement into physics, with [[Percolation_theory|percolation theory]] setting the thresholds where connectivity appears and collapses. The same instruments read the [[Internet|Internet]] and [[World_Wide_Web|World Wide Web]], the [[Telecommunications_network|telecommunications network]] and [[Computer_network|computer network]], [[Social_network_analysis|social network analysis]] in [[Sociology|sociology]], [[Epidemiology|epidemic]] spread through [[Compartmental_models_(epidemiology)|compartmental models]], and every [[Complex_network|complex network]] an [[Agent-based_model|agent-based model]] or [[Complex_system|complex-system]] study cares to wire. ## Wikipedia : Wikitube **Strict pair:** [Wikipedia](https://en.wikipedia.org/wiki/Network_theory) : [Wikitube](https://en.wikitube.io/wiki/Network_theory) ## Previous hub tags Hubs: `Systems`. Portals: [[PORTAL_Systems]], [[PORTAL_Network_theory]].