M3 Math Majors Matter ----------------------------------


           Julien Langou

Julien Langou is the newest member of the mathematics department.
Where were you born?
Meaux in France.
Where did you get your undergraduate degree?
My B.S. is from Lycee Hoche, Versailles
Did you start college majoring in mathematics? If not, what was your major?
B.S. in Mathematics, M.S. is in Aeronautic Engineering Option Propulsion
What courses or areas of study gave you trouble while you were an undergraduate?
Everything that was not Math: Physics, Chemistry, and even English.
What math class was the most challenging for you?
I was lucky to get two excellent teachers while I was an undergrad, so this went along pretty well. Things became challenging when I started my classes for my Ph.D. after an Engineering Master's Degree. I still remember my first class on Sobolev spaces. This was a bit too much abstract after three years in Engineering.
When did you realize that math was of interest to you?
Math is challenging, satisfactory and fun. My teachers always gave me some challenging problems and it was a big accomplishment to solve them. Now that I have grown up, I find my own challenge/satisfaction/fun in Math through my research and teaching. I love to challenge my students, for example.
How did you know which area of mathematics to pursue?
Although I am a Mathematician, I received a good education in Physics. This has oriented my interests towards Applied Mathematics and Scientific Computing.
What do you consider to be your biggest accomplishment as an undergraduate?
I made a road for square wheels! This was great. The equation is a cosh, if I remember well. The road is on display in my office for the curious ones.
What would you have done differently as an undergraduate?
I had too much focus on what I liked and maybe not enough on what I liked less. This was a mistake. I should have kept more balance in my work.
What was your most embarrassing moment as an undergrad?
This was quite embarrassing. This began on a Friday night. Exam was on Saturday --there was one exam per week. I was working in my room with my two roommates, each of us working on an individual book of last years' exams. It was late and we were late in the preparation of the Saturday exam, so we decided that each of us was to do a different exam on our own, explain it to the others, and all three of us would go to bed after that. We picked three exams from three different books. When it was my time to explain the solution, everybody was tired, and the exam we picked was really hard and not really focused on what we were supposed to have the following Saturday. So, we skipped my presentation. Guess what. The "really hard" exam was on our desk the Saturday morning. Took me some time to quiet my two friends after that.
What advice would you give to undergraduate math majors?
Be voluntary in class and outside class.
If you are really stuck on a problem, get some help.
Add some scope to your education: 1) understand why the material you are learning is important -- yes, it is important to master this material to earn your degree, but try to find another, maybe better, motivation, 2) for some specific topics, get interested in some research aspect around it. What is the state of the art? What are the open problems? 3) Gain more math culture -- who are behind the names, when did they live, why did they need to discover this and finally try to make the connection with the present.
Are you the first PhD in your family?
Yep, daddy is a farmer, and mummy is a teacher in the K-12 system.
Where did you complete your PhD studies?
CERFACS Toulouse, Parallel Algorithm team: http://www.cerfacs.fr
Describe your area of research.
In general, the equations that our Physicist friends want to solve are way too hard to have an analytic solution and the only way to go is to obtain a numerical solution (i.e. you do not know a closed form formula but you have a way to generate any numerical data related to your solution).

In a simplified word, physicists generate a set of equations from which they are seeking the solution. The Numerical Analysis folks take the equation and derive algorithms to solve the problem numerically. Computer Scientists take the Numerical Analysis algorithms and implement them efficiently on various computing machine. Computer Scientists also make software available and useable by the Physicists. In fine, the loop is looped and some new challenging Physics can be done leading to all kind of great discoveries.

Numerical Analysis is a very exciting field in the sense that it has a wide range of direct applicability and there is a real demand for solving the challenging new problems that are arising. My interest is in Numerical Linear Algebra (how to compute eigenvalues of large matrices, how to solve large linear systems of equations). One of the characteristics of my research is that I am making publicly available and maintaining my research software. This enables Physicists to be able to use state of the art methods to solve their problems.

Why did you decide to join the faculty at UCDHSC?
I always wanted to be teaching and after seven years of full-time research, it was a now-or-never point in my life. So I made the step and moved from full-time research to a faculty position. Why UCDHSC? The CCM (Center for Computational Mathematics) is well known around the States. It is a great opportunity for me to get involved and work with this group. Furthermore, when I visited the Department I had excellent contact with all the people I met. My feeling is that at UCDHSC I can find some support to help me succeed in term of teaching and research, the philosophy being that my success is the success of the Department. Well, even though this seems a reasonable statement, it was hard to find a place like this one.
What do you think is the biggest misconception about mathematicians?
The importance of a Mathematical statement is proportional to the complexity of its proof. (This is a misconception. Some powerful ideas can be expressed clearly and concisely. For example, the paper of Householder on QR factorization (1958) and the paper of Cooley and Turkey (1965) on FFT are both less than 5 pages.)
How can an undergraduate get involved with the math department?
The best is to be on-place. For example, show up once a week in the CU Building. Take your homework with you. Put you on a table and work here. This is a quiet and studious place and you will meet and interact with other people. Also, the faculty might start some student project and it is a good idea to participate in those projects if you have time for this.
Where is your favorite place you have ever traveled?
Well being an expatriate, what I am looking the most forward these days is going home from time to time to meet with my family in France. But otherwise and to be more fancy, I liked a lot New Zealand, Italy, and Crete.
What CD is in your car right now?
1) My wife has my car, 2) It's an old Dodge Caravan 95 with no CD reader in it, and 3) if we are listening to something, it is the radio.
What is your favorite movie?
"True Romance"
What is the best concert you have ever been to?
Ben Harper
What would you be doing if you weren't a math faculty member?
1) Full-time research scientist in a lab, 2) Aeronautic Engineer, or 3) Farmer
What is your favorite thing to do in your free time?
Spend time with my family. In general, to resume outdoor activities
What is your favorite sport?
If you could have lunch with anyone, living or dead, who would it be?
My grandfathers.
Even though you have only been in Colorado a short time, what do you hope to do in the state in the upcoming months?
Great Sand Dunes.
Outside of the university setting, what is the biggest difference between Denver and your previous residence?
My previous residence is three years in Knoxville, Tennessee. Some differences ...
Tell us something about yourself that would surprise everyone.
I can juggle with five balls (well ... "I could juggle" would be more accurate). But I have never managed to ride a monocycle despite several attempts.

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