## Welcome to Yongheng Zhang's Homepage!

### Interests

Algebraic topology. Homotopy theory. And applications. I think about configuration spaces (and their variants) of points in spaces and using them to probe questions in algebra, geometry and topology.

### Publication

Kaufmann, Ralph M.; Zhang, Yongheng **Permutohedral structures on E _{2}-operads**.

*Forum Math.*29 (2017), no. 6, 1371-1411.

Zhang, Yongheng **Circle deformation in Hacon's sphere eversion**. Bridges Conf. Proc., Online, Aug 2021, 265-268.

Wei, Annie; Zhang, Yongheng **Wave, Boy's Surface, and Machine**. Bridges Conf. Proc., Aalto, Aug 2022, 17-24.

### Art

**几何y代数 Merry-Go-Round**, July-December 2023.

### Preprint

Koytcheff, Robin; Zhang, Yongheng **Cubes, cacti, and framed long knots**. under review.

Zhang, Yongheng **Recollection and Reflection: *** From Euler to Lagrange in 1Q84*.

Zhang, Yongheng **Line Integral and Area Without Green**.

### Current Teaching (Fall 2023)

- MATH 211 Multivariable Calculus
- MATH 345 Functions of a Complex Variable

### Regular Office Hours

- M W 11-11:50 AM, 1-2:50 PM
- Th 9:00-10:50 AM

### Office Location

- SMUD 510

### Previous Teaching

- MATH 105 Calculus with Algebra (f19, f22: Coraline)
- MATH 111 Introduction to the Calculus (f15)
- MATH 211 Multivariable Calculus (f15, s16, f16, s17, f17, s18, f18, s19, f19, s20, f20, s21, f21, s22, f22, s23)
- MATH 260 Differential Equations (s18: fiction by Cindy Lopez)
- MATH 345 Functions of a Complex Variable (f16: poem by Greg Carroll, f18: online game by Sai Chauhan)
- MATH 350 Groups, Rings and Fields (f17, s19)
- MATH 355 Introduction to Analysis (s16, s20)
- MATH 455 Topology (s17: 50 lessons [90MB] 50 lessons without notes [20MB])

### Teaching at Purdue

- Geometry for Elementary Teachers
- Topology for High School Students (notes by Hannah Burnau)
- Calculus I, II, III
- Linear Algebra
- ODE and basic PDE

### Living Proof

### Where Theory meets Chalk, Dust Flies

### Math from Three to Seven by Zvonkin

### Tokyo 2020 Emblems

### The Last Voyage of Ulysses & Pierced by a Sun Ray

### Mathematical Omnibus: Thirty Lectures on Classical Mathematics

(It contains a very clear exposition on an accessible proof of the insolvability of the quintic, and much more.)

### What does it feel like doing mathematical research?

Like what is described in this music video. (turn on the English translation)

By the way, we wander around and do this kind of dance a lot after school in the 1990s, before being found by parents and dragged back home.