David Hilbert
The life of David Hilbert - The Mathematician Who Redefined Truth
Einstein-Hilbert Action
The action that yields the Einstein field equations of general relativity.
\[ S = \int \sqrt{-g} R \, d^4x \]
Hilbert Space Inner Product
Generalizing Euclidean space to infinite dimensions.
\[ \langle f, g \rangle = \int_a^b f(x) \overline{g(x)} \, dx \]
Sources: https://mathshistory.st-andrews.ac.uk/Biographies/Hilbert/
