All reports by Author Partha Mukhopadhyay:

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TR24-073
| 11th April 2024
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Vikraman Arvind, Abhranil Chatterjee, Partha Mukhopadhyay#### Trading Determinism for Noncommutativity in Edmonds' Problem

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TR22-071
| 13th May 2022
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Arkadev Chattopadhyay, Utsab Ghosal, Partha Mukhopadhyay#### Robustly Separating the Arithmetic Monotone Hierarchy Via Graph Inner-Product

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TR22-067
| 4th May 2022
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Vikraman Arvind, Abhranil Chatterjee, Partha Mukhopadhyay#### Black-box Identity Testing of Noncommutative Rational Formulas of Inversion Height Two in Deterministic Quasipolynomial-time

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TR20-191
| 27th December 2020
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Arkadev Chattopadhyay, Rajit Datta, Partha Mukhopadhyay#### Negations Provide Strongly Exponential Savings

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TR20-166
| 9th November 2020
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Arkadev Chattopadhyay, Rajit Datta, Partha Mukhopadhyay#### Lower Bounds for Monotone Arithmetic Circuits Via Communication Complexity

Revisions: 1

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TR19-063
| 28th April 2019
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Vikraman Arvind, Abhranil Chatterjee, Rajit Datta, Partha Mukhopadhyay#### Efficient Black-Box Identity Testing for Free Group Algebra

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TR16-089
| 2nd June 2016
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Vikraman Arvind, Partha Mukhopadhyay, Raja S#### Randomized Polynomial Time Identity Testing for Noncommutative Circuits

Revisions: 2

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TR15-052
| 6th April 2015
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Partha Mukhopadhyay#### Depth-4 Identity Testing and Noether's Normalization Lemma

Revisions: 1

Vikraman Arvind, Abhranil Chatterjee, Partha Mukhopadhyay

Let $X=X_1\sqcup X_2\sqcup\ldots\sqcup X_k$ be a partitioned set of variables such that the variables in each part $X_i$ are noncommuting but for any $i\neq j$, the variables $x \in X_i$ commute with the variables $x' \in X_j$. Given as input a square matrix $T$ whose entries are linear forms over ... more >>>

Arkadev Chattopadhyay, Utsab Ghosal, Partha Mukhopadhyay

We establish an $\epsilon$-sensitive hierarchy separation for monotone arithmetic computations. The notion of $\epsilon$-sensitive monotone lower bounds was recently introduced by Hrubes [Computational Complexity'20]. We show the following:

(1) There exists a monotone polynomial over $n$ variables in VNP that cannot be computed by $2^{o(n)}$ size monotone ...
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Vikraman Arvind, Abhranil Chatterjee, Partha Mukhopadhyay

Hrube\v{s} and Wigderson (2015) initiated the complexity-theoretic study of noncommutative formulas with inverse gates. They introduced the Rational Identity Testing (RIT) problem which is to decide whether a noncommutative rational formula computes zero in the free skew field. In the white-box setting, deterministic polynomial-time algorithms are known for this problem ... more >>>

Arkadev Chattopadhyay, Rajit Datta, Partha Mukhopadhyay

We show that there is a family of monotone multilinear polynomials over $n$ variables in VP, such that any monotone arithmetic circuit for it would be of size $2^{\Omega(n)}$. Before our result, strongly exponential lower bounds on the size of monotone circuits were known only for computing explicit polynomials in ... more >>>

Arkadev Chattopadhyay, Rajit Datta, Partha Mukhopadhyay

Valiant (1980) showed that general arithmetic circuits with negation can be exponentially more powerful than monotone ones. We give the first qualitative improvement to this classical result: we construct a family of polynomials $P_n$ in $n$ variables, each of its monomials has positive coefficient, such that $P_n$ can be computed ... more >>>

Vikraman Arvind, Abhranil Chatterjee, Rajit Datta, Partha Mukhopadhyay

Hrubeš and Wigderson [HW14] initiated the study of

noncommutative arithmetic circuits with division computing a

noncommutative rational function in the free skew field, and

raised the question of rational identity testing. It is now known

that the problem can be solved in deterministic polynomial time in

more >>>

Vikraman Arvind, Partha Mukhopadhyay, Raja S

In this paper we show that polynomial identity testing for

noncommutative circuits of size $s$, computing a polynomial in

$\mathbb{F}\langle z_1,z_2,\cdots,z_n \rangle$, can be done by a randomized algorithm

with running time polynomial in $s$ and $n$. This answers a question

that has been open for over ten years.

The ... more >>>

Partha Mukhopadhyay

We consider the \emph{black-box} polynomial identity testing problem for a sub-class of

depth-4 circuits. Such circuits compute polynomials of the following type:

$

C(x) = \sum_{i=1}^k \prod_{j=1}^{d_i} Q_{i,j},

$

where $k$ is the fan-in of the top $\Sigma$ gate and $r$ is the maximum degree of the ...
more >>>