# List of things named after Leonhard Euler

In mathematics and physics, there are a large number of topics named in honor of Swiss mathematician Leonhard Euler (1707–1783), who made many important discoveries and innovations. Many of these items named after Euler include their own unique function, equation, formula, identity, number (single or sequence), or other mathematical entity. Many of these entities have been given simple and ambiguous names such as Euler's function, Euler's equation, and Euler's formula.

Euler's work touched upon so many fields that he is often the earliest written reference on a given matter. In an effort to avoid naming everything after Euler, some discoveries and theorems are attributed to the first person to have proved them after Euler.

## Euler's equations

Usually, Euler's equation refers to one of (or a set of) differential equations (DEs). It is customary to classify them into ODEs and PDEs.

Otherwise, Euler's equation might refer to a non-differential equation, as in these three cases:

## Topics by field of study

Selected topics from above, grouped by subject.

### Graph theory

• Euler characteristic (formerly called Euler number) in algebraic topology and topological graph theory, and the corresponding Euler's formula $\chi (S^{2})=F-E+V=2$
• Eulerian circuit, Euler cycle or Eulerian path – a path through a graph that takes each edge once
• Eulerian graph has all its vertices spanned by an Eulerian path
• Euler class
• Euler diagram – incorrectly, but more popularly, known as Venn diagrams, its subclass
• Euler tour technique