---
date: '2025-11-07'
description: 18.156 | Spring 2025 | Graduate
id: projection theory
modified: 2026-06-05 15:08:05 GMT-04:00
socials:
  ocw: https://ocw.mit.edu/courses/18-156-projection-theory-spring-2025/
tags:
  - math
title: projection theory
created: '2025-11-07'
published: '2025-11-07'
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The class studies projection theory, starting from the first questions and building up to recent developments. Projection theory studies how a set X behaves under different orthogonal projections. Questions of this type aren’t usually emphasized in the graduate analysis curriculum, but they come up in many areas of math, including harmonic analysis, analytic number theory, additive combinatorics, and homogeneous dynamics.