#functional-analysis

5 posts

May 23, 2026

Summary of the Talk on Stability of Matter and Mathematical Physics in Vienna

What follows is an AI generated ( notegpt.io, found by google ) summary of Rupert’s recent talk at the Erwin Schrödinger International Institute for Mathematics...

maths functional-analysis ai-assisted rough talk stability-of-matter chinese-translation

May 19, 2026

Notes on Lewin Ch4: Spectral Theorem and Functional Calculus

1 Multiplication Operators Let $𝐵 \subset ℝ^{𝑑}$ be Borel, and let $𝜇$ be a locally finite Borel measure on $𝐵$ . We set $ℌ = 𝐿^{2} (𝐵, d 𝜇; ℂ)$ . Local finiteness implies that...

maths functional-analysis self-adjointness notes rough

May 15, 2026

Notes on Lewin Ch3: Self-adjointness Criteria: Rellich, Kato and Friedrichs

Rellich–Kato Let $(𝐴, 𝐷 (𝐴))$ be a self-adjoint operator and $0 \leq 𝛼 < 1$ . We say that an operator $𝐵$ defined on $𝐷 (𝐴)$ is $𝐴$ -bounded with relative bound $𝛼$ if...

maths functional-analysis self-adjointness notes rough

May 7, 2026

Notes on Lewin Ch2: Self-adjointness

Let $ℌ$ be a separable Hilbert space over $ℂ$ . Graphs Definition: the graph of an operator $(𝐴, 𝐷 (𝐴))$ is the vector subpsace of $ℌ \times ℌ$ given by...

maths functional-analysis notes rough

April 24, 2024

Notes on Lewin Appendix

Appendix A: Sobolev Spaces Definition Definition of $𝑊^{𝑘, 𝑝}$ is given, and the Meyer-Serrin theorem $𝐻 = 𝑊$ is stated without proof. Sobolev spaces on the interval Considering...

maths notes quantum-mechanics sobolev-spaces functional-analysis rough