[PAST EVENT] Mathematics Colloquium - Shuxing Li (Univ of Delaware)

April 11, 2025
2pm - 3pm
Location
Jones Hall, Room 301
200 Ukrop Way
Williamsburg, VA 23185Map this location
Access & Features
  • Free food
  • Open to the public
coding fractal by inspirito

Counting Fearlessly and Meticulously: Weight Distribution of Cyclic Codes with Generalized Niho-type Nonzeros

Determining the minimum Hamming distance of an error-correcting code C has long stood as a fundamental challenge in coding theory. In this talk, we turn our attention to an even more ambitious problem: determining the full weight distribution of C. This means counting the number of codewords in C of each possible Hamming weight—an essential but notoriously difficult task, especially for general codes.

While computing the weight distribution for an arbitrary code remains largely out of reach, the problem becomes more tractable under additional structural assumptions. Specifically, if the code C is cyclic, one can follow a well-established approach to reduce the problem to the number-theoretic task of evaluating certain exponential sums.

In this talk, we focus on a family of cyclic codes characterized by generalized Niho-type nonzeroes. For these codes, we succeed in determining the value distribution of the associated exponential sums through a process of fearless and meticulous counting. Our approach draws upon a rich toolkit of mathematical ingredients, including exponential sums, elementary symmetric polynomials, binary Zetterberg codes, and the analysis of Vandermonde-like homogeneous linear systems.


Sponsored by: Mathematics

Contact

Eric Swartz