 # Huy Dang

## Contacts

Email: hqd4bz (at) virginia (dot) edu
Office: Kerchof 401
Office Hours: W 2:00 - 3:00.

I am a fifth-year graduate student at the University of Virginia. My thesis advisor is Andrew Obus. My research interests are arithmetic geometry, algebraic number theory, and Galois theory. In particular, I am working on the lifting problem for curves and deformations of wildly ramified covers. Before graduate school, I worked as a mechanical engineer (designing injection mold for plastic parts) for a year.

Here is my CV!

## Publications

1. Connectedness of the Moduli space of Artin-Schreier curves of fixed genus, 2018. Submitted. In this paper, we show that the moduli space of Artin-Schreier covers (Z/p-covers over an algebraically closed field of characteristic p>0) of a given genus g is connected when g is sufficiently large.

2. The refined local lifting problem for Z/4 covers, 2019. Draft. The refined lifting problem asks whether a local cyclic extension is liftable in towers. That means, suppose we are given a local G-extension k[[z]]/k[[t]] with G cyclic and a lift R[[S]]/R[[T]] of a subextension k[[s]]/k[[t]] to characteristic zero, is there a lift of k[[z]]/k[[t]] to characteristic zero that containing R[[S]]/R[[T]] as a subextension? One can learn more about the lifting problem from this paper written by Andrew Obus. So far, we are able to answer the question for most of the cases when k has characteristic 2. In particular, the answer is always yes when G=Z/4 × Z/m (m is odd).

## Working Projects

1. Equicharacteristic deformations of Artin-Schreier covers. Draft, available upon request. Let R=k[[t]] where char k=p>0. Given an order p^n-automorphism of a formal disc over R. One can derive the minimal semi-stable model for which the specializations of fixed points are distinct and lie in the smooth locus of the special fiber. The description leads to a combinatorial object which resembles a Hurwitz tree in mixed characteristic (0,p), which we give the same name. The existence of a Hurwitz tree is known to give a necessary condition for the existence of a p-automorphism whose ramification data fit into that tree. We prove that the conditions imposed by the Hurwitz tree's structure are also sufficient. Here is the poster about the project that I presented at the conference Ideals, Varieties, Applications.

## Teaching

Instructor of Record:

2018 Fall, Math 1210, Applied Calculus I
2017 Fall, Math 1310, Calculus I
2017 Spring, Math 1210 Applied Calculus I
2016 Fall, Math 1210 Applied Calculus I
2016 Spring, Math 1220 Applied Calculus II
2015 Fall, Math 1210 Applied Calculus I

Teaching Assistant:

2019 Summer, Math 1310, Calculus I
2019 Spring, MATH 4652, Introduction to Abstract Algebra and Math 1310, Calculus I
2018 Spring, Math 1320, Calculus II
2017 Summer, Math 1320, Calculus II
2015 Summer, Math 1310, Calculus I
2015 Spring, Math 5656, Number Theory and Math 1330, Calculus III
2014 Fall, Math 1310, Calculus I (2 sections)

## Engineering Stuffs

I got a Bachelor in Mechanical Engineering and worked as a mechanical engineer for a year in Vietnam. Below are some of the simulation videos I made for my projects back in College.

1. Metal Clip Machine, 2009
2. Automatic Sorting System 1, 2009
3. Automatic Sorting System 2, 2009

My bachelor thesis (in Vietnamese) was about designing and constructing a model of pipe conveyor. Here are the drawings and some photos of the real model.   