Definition:Neumann Series
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Definition
Let $T$ be an operator.
Let $\circ$ denote the composition.
Let $I$ be the identity mapping.
For any $k \in \N$ let $T^k = \underbrace{T \circ T \circ \ldots \circ T \circ T}_{k \text{ times} }$ and $T^0 = I$
Then the series $\ds \sum_{k \mathop = 0}^\infty T^k$ are known as Neumann series.
Also see
- Results about Neumann series can be found here.
Source of Name
This entry was named for Carl Gottfried Neumann.
Sources
- 2017: Amol Sasane: A Friendly Approach to Functional Analysis ... (previous) ... (next): Chapter $\S 2.4$: Composition of continuous linear transformations