Visu Makam

Invariant Theory and wheeled PROPs

Harm Derksen, Visu Makam

Journal article  |  2023  |  Journal of Pure and Applied Algebra

Ranks of linear matrix pencils separate simultaneous similarity orbits

H Derksen, I Klep, V Makam, J Volčič

Journal article  |  2023  |  Advances in Mathematics

This paper solves the two-sided version and provides a counterexample to the general version of the 2003 conjecture by Hadwin and ..

Lower Bounds for Maximally Recoverable Tensor Codes and Higher Order MDS Codes

J Brakensiek, S Gopi, V Makam

Journal article  |  2022  |  IEEE Transactions on Information Theory

An (m,n,a,b)-tensor code consists of m×n matrices whose columns satisfy 'a' parity checks and rows satisfy 'b' parity checks (i.e...

Subrank and Optimal Reduction of Scalar Multiplications to Generic Tensors

H Derksen, V Makam, J Zuiddam

Conference Proceedings  |  2022  |  Leibniz International Proceedings in Informatics, LIPIcs

Maximum likelihood estimation for tensor normal models via castling transforms

H Derksen, V Makam, M Walter

Journal article  |  2022  |  Forum of Mathematics, Sigma

In this paper, we study sample size thresholds for maximum likelihood estimation for tensor normal models. Given the model paramet..

Polystability in positive characteristic and degree lower bounds for invariant rings

H Derksen, V Makam

Journal article  |  2022  |  Journal of Combinatorial Algebra

We develop a representation theoretic technique for detecting closed orbits that is applicable in all characteristics. Our techniq..

Singular tuples of matrices is not a null cone (and the symmetries of algebraic varieties)

Visu Makam, Avi Wigderson

Journal article  |  2021  |  JOURNAL FUR DIE REINE UND ANGEWANDTE MATHEMATIK

The following multi-determinantal algebraic variety plays a central role in algebra, algebraic geometry and computational complexi..

Polynomial time algorithms in invariant theory for torus actions

P Bürgisser, ML Doğan, V Makam, M Walter, A Wigderson

Conference Proceedings  |  2021  |  Leibniz International Proceedings in Informatics, LIPIcs

An action of a group on a vector space partitions the latter into a set of orbits. We consider three natural and useful algorithmi..

ON THE TENSOR RANK OF THE 3 x 3 PERMANENT AND DETERMINANT

Siddharth Krishna, Visu Makam

Journal article  |  2021  |  ELECTRONIC JOURNAL OF LINEAR ALGEBRA

The tensor rank and border rank of the 3 × 3 determinant tensor are known to be 5 if the characteristic is not two. In characteris..

Maximum Likelihood Estimation for Matrix Normal Models via Quiver Representations

Harm Derksen, Visu Makam

Journal article  |  2021  |  SIAM JOURNAL ON APPLIED ALGEBRA AND GEOMETRY

We study the log-likelihood function and maximum likelihood estimate (MLE) for the matrix normal model for both real and complex m..