All reports in year 2021:

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TR21-066
| 5th May 2021
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Lianna Hambardzumyan, Hamed Hatami, Pooya Hatami#### Dimension-free Bounds and Structural Results in Communication Complexity

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TR21-065
| 5th May 2021
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Nikhil Mande, Swagato Sanyal#### One-way communication complexity and non-adaptive decision trees

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TR21-064
| 5th May 2021
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Noah Singer, Madhu Sudan, Santhoshini Velusamy#### Streaming approximation resistance of every ordering CSP

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TR21-063
| 3rd May 2021
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Chi-Ning Chou, Alexander Golovnev, Madhu Sudan, Santhoshini Velusamy#### Approximability of all finite CSPs in the dynamic streaming setting

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TR21-062
| 29th April 2021
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Vishwas Bhargava, Sumanta Ghosh#### Improved Hitting Set for Orbit of ROABPs

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TR21-061
| 29th April 2021
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Noah Fleming, Toniann Pitassi#### Reflections on Proof Complexity and Counting Principles

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TR21-060
| 8th April 2021
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Klim Efremenko, Gillat Kol, Raghuvansh Saxena#### Optimal Error Resilience of Adaptive Message Exchange

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TR21-059
| 20th April 2021
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Yanyi Liu, Rafael Pass#### On One-way Functions from NP-Complete Problems

Revisions: 1

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TR21-058
| 21st April 2021
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Shuichi Hirahara#### Average-Case Hardness of NP from Exponential Worst-Case Hardness Assumptions

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TR21-057
| 23rd April 2021
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Hanlin Ren, Rahul Santhanam#### Hardness of KT Characterizes Parallel Cryptography

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TR21-056
| 22nd April 2021
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Yanyi Liu, Rafael Pass#### On the Possibility of Basing Cryptography on $\EXP \neq \BPP$

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TR21-055
| 20th April 2021
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Yanyi Liu, Rafael Pass#### Cryptography from Sublinear-Time Average-Case Hardness of Time-Bounded Kolmogorov Complexity

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TR21-054
| 14th April 2021
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James Cook, Ian Mertz#### Encodings and the Tree Evaluation Problem

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TR21-053
| 13th April 2021
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Jan Krajicek#### Information in propositional proofs and algorithmic proof search

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TR21-052
| 12th April 2021
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Benny Applebaum, Oded Nir#### Upslices, Downslices, and Secret-Sharing with Complexity of $1.5^n$

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TR21-051
| 8th April 2021
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Klim Efremenko, Gillat Kol, Raghuvansh Saxena#### Binary Interactive Error Resilience Beyond $1/8$ (or why $(1/2)^3 > 1/8$)

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TR21-050
| 2nd April 2021
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Marshall Ball, Alper Cakan, Tal Malkin#### Linear Threshold Secret-Sharing with Binary Reconstruction

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TR21-049
| 1st April 2021
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Juraj Hromkovic#### Kolmogorov complexity and nondeterminism versus determinism for polynomial time computations

Revisions: 1

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TR21-048
| 27th March 2021
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William Hoza#### Better Pseudodistributions and Derandomization for Space-Bounded Computation

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TR21-047
| 26th March 2021
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Zander Kelley, Raghu Meka#### Random restrictions and PRGs for PTFs in Gaussian Space

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TR21-046
| 22nd March 2021
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Uma Girish, Avishay Tal, Kewen Wu#### Fourier Growth of Parity Decision Trees

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TR21-045
| 22nd March 2021
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Vishwas Bhargava, Shubhangi Saraf, Ilya Volkovich#### Reconstruction Algorithms for Low-Rank Tensors and Depth-3 Multilinear Circuits

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TR21-044
| 14th February 2021
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Alexander Kulikov, Nikita Slezkin#### SAT-based Circuit Local Improvement

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TR21-043
| 15th March 2021
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Peter Dixon, A. Pavan, N. V. Vinodchandran#### Promise Problems Meet Pseudodeterminism

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TR21-042
| 16th March 2021
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Dana Moshkovitz#### Strong Parallel Repetition for Unique Games on Small Set Expanders

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TR21-041
| 15th March 2021
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Zhenjian Lu, Igor Carboni Oliveira#### An Efficient Coding Theorem via Probabilistic Representations and its Applications

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TR21-040
| 15th March 2021
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Lijie Chen, Zhenjian Lu, Xin Lyu, Igor Carboni Oliveira#### Majority vs. Approximate Linear Sum and Average-Case Complexity Below NC1

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TR21-039
| 15th March 2021
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Zhenjian Lu, Igor Carboni Oliveira, Rahul Santhanam#### Pseudodeterministic Algorithms and the Structure of Probabilistic Time

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TR21-038
| 15th March 2021
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Alessandro Chiesa, Fermi Ma, Nicholas Spooner, Mark Zhandry#### Post-Quantum Succinct Arguments

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TR21-037
| 1st March 2021
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Prerona Chatterjee#### Separating ABPs and Some Structured Formulas in the Non-Commutative Setting

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TR21-036
| 14th March 2021
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Siddharth Bhandari, Prahladh Harsha, Mrinal Kumar, Madhu Sudan#### Ideal-theoretic Explanation of Capacity-achieving Decoding

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TR21-035
| 13th March 2021
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Robert Robere, Jeroen Zuiddam#### Amortized Circuit Complexity, Formal Complexity Measures, and Catalytic Algorithms

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TR21-034
| 9th March 2021
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Oded Goldreich#### Robust Self-Ordering versus Local Self-Ordering

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TR21-033
| 7th March 2021
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Susanna de Rezende#### Automating Tree-Like Resolution in Time $n^{o(\log n)}$ Is ETH-Hard

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TR21-032
| 5th March 2021
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Justin Holmgren, Alex Lombardi, Ron Rothblum#### Fiat-Shamir via List-Recoverable Codes (or: Parallel Repetition of GMW is not Zero-Knowledge)

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TR21-031
| 3rd March 2021
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Vaibhav Krishan#### Upper Bound for Torus Polynomials

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TR21-030
| 2nd March 2021
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Shuichi Hirahara, Rahul Ilango, Bruno Loff#### Hardness of Constant-round Communication Complexity

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TR21-029
| 1st March 2021
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Inbar Kaslasi, Ron Rothblum, Prashant Nalini Vasudevan#### Public-Coin Statistical Zero-Knowledge Batch Verification against Malicious Verifiers

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TR21-028
| 27th February 2021
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Anastasia Sofronova, Dmitry Sokolov#### Branching Programs with Bounded Repetitions and $\mathrm{Flow}$ Formulas

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TR21-027
| 24th February 2021
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Lijie Chen, Gillat Kol, Dmitry Paramonov, Raghuvansh Saxena, Zhao Song, Huacheng Yu#### Almost Optimal Super-Constant-Pass Streaming Lower Bounds for Reachability

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TR21-026
| 23rd February 2021
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Joshua Brakensiek, Venkatesan Guruswami, Sai Sandeep#### Conditional Dichotomy of Boolean Ordered Promise CSPs

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TR21-025
| 15th February 2021
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Sivakanth Gopi, Venkatesan Guruswami#### Improved Maximally Recoverable LRCs using Skew Polynomials

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TR21-024
| 15th February 2021
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Mika Göös, Gilbert Maystre#### A Majority Lemma for Randomised Query Complexity

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TR21-023
| 20th February 2021
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Jiatu Li, Tianqi Yang#### $3.1n - o(n)$ Circuit Lower Bounds for Explicit Functions

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TR21-022
| 20th February 2021
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Stefan Dantchev, Nicola Galesi, Abdul Ghani, Barnaby Martin#### Depth lower bounds in Stabbing Planes for combinatorial principles

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TR21-021
| 18th February 2021
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Per Austrin, Kilian Risse#### Average-Case Perfect Matching Lower Bounds from Hardness of Tseitin Formulas

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TR21-020
| 15th February 2021
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Gil Cohen, Dean Doron, Oren Renard, Ori Sberlo, Amnon Ta-Shma#### Error Reduction For Weighted PRGs Against Read Once Branching Programs

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TR21-019
| 17th February 2021
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Edward Pyne, Salil Vadhan#### Pseudodistributions That Beat All Pseudorandom Generators

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TR21-018
| 20th February 2021
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Dean Doron, Raghu Meka, Omer Reingold, Avishay Tal, Salil Vadhan#### Monotone Branching Programs: Pseudorandomness and Circuit Complexity

Revisions: 1

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TR21-017
| 19th February 2021
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Timothy Gowers, Emanuele Viola#### Mixing in non-quasirandom groups

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TR21-016
| 16th February 2021
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Shalev Ben-David, Mika Göös, Siddhartha Jain, Robin Kothari#### Unambiguous DNFs from Hex

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TR21-015
| 15th February 2021
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Chandan Saha, Bhargav Thankey#### Hitting Sets for Orbits of Circuit Classes and Polynomial Families

Revisions: 2

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TR21-014
| 15th February 2021
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Dori Medini, Amir Shpilka#### Hitting Sets and Reconstruction for Dense Orbits in VP$_e$ and $\Sigma\Pi\Sigma$ Circuits

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TR21-013
| 20th January 2021
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Srinivasan Arunachalam, Penghui Yao#### Positive spectrahedrons: Geometric properties, Invariance principles and Pseudorandom generators

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TR21-012
| 9th February 2021
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Noah Fleming, Mika Göös, Russell Impagliazzo, Toniann Pitassi, Robert Robere, Li-Yang Tan, Avi Wigderson#### On the Power and Limitations of Branch and Cut

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TR21-011
| 13th February 2021
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Chi-Ning Chou, Alexander Golovnev, Madhu Sudan, Santhoshini Velusamy#### Classification of the streaming approximability of Boolean CSPs

Revisions: 2
,
Comments: 1

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TR21-010
| 11th February 2021
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Eric Allender, John Gouwar, Shuichi Hirahara, Caleb Robelle#### Cryptographic Hardness under Projections for Time-Bounded Kolmogorov Complexity

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TR21-009
| 1st February 2021
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Eric Allender, Mahdi Cheraghchi, Dimitrios Myrisiotis, Harsha Tirumala, Ilya Volkovich#### One-way Functions and Partial MCSP

Revisions: 1
,
Comments: 1

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TR21-008
| 30th January 2021
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Akash Kumar, C. Seshadhri, Andrew Stolman#### Random walks and forbidden minors III: poly(d/?)-time partition oracles for minor-free graph classes

Revisions: 3

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TR21-007
| 14th January 2021
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Sai Sandeep#### Almost Optimal Inapproximability of Multidimensional Packing Problems

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TR21-006
| 18th January 2021
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Susanna de Rezende, Jakob Nordström, Marc Vinyals#### How Limited Interaction Hinders Real Communication (and What It Means for Proof and Circuit Complexity)

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TR21-005
| 13th January 2021
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Anindya De, Elchanan Mossel, Joe Neeman#### Robust testing of low-dimensional functions

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TR21-004
| 10th January 2021
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Vishnu Iyer, Avishay Tal, Michael Whitmeyer#### Junta Distance Approximation with Sub-Exponential Queries

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TR21-003
| 6th January 2021
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Lijie Chen, Xin Lyu#### Inverse-Exponential Correlation Bounds and Extremely Rigid Matrices from a New Derandomized XOR Lemma

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TR21-002
| 8th January 2021
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Pooya Hatami, William Hoza, Avishay Tal, Roei Tell#### Fooling Constant-Depth Threshold Circuits

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TR21-001
| 1st January 2021
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Klim Efremenko, Gillat Kol, Dmitry Paramonov, Raghuvansh Saxena#### Computation Over the Noisy Broadcast Channel with Malicious Parties

Lianna Hambardzumyan, Hamed Hatami, Pooya Hatami

The purpose of this article is to initiate a systematic study of dimension-free relations between basic communication and query complexity measures and various matrix norms. In other words, our goal is to obtain inequalities that bound a parameter solely as a function of another parameter. This is in contrast to ... more >>>

Nikhil Mande, Swagato Sanyal

We study the relationship between various one-way communication complexity measures of a composed function with the analogous decision tree complexity of the outer function. We consider two gadgets: the AND function on 2 inputs, and the Inner Product on a constant number of inputs. Let $IP$ denote Inner Product on ... more >>>

Noah Singer, Madhu Sudan, Santhoshini Velusamy

An ordering constraint satisfaction problem (OCSP) is given by a positive integer $k$ and a constraint predicate $\Pi$ mapping permutations on $\{1,\ldots,k\}$ to $\{0,1\}$. Given an instance of OCSP$(\Pi)$ on $n$ variables and $m$ constraints, the goal is to find an ordering of the $n$ variables that maximizes the number ... more >>>

Chi-Ning Chou, Alexander Golovnev, Madhu Sudan, Santhoshini Velusamy

A constraint satisfaction problem (CSP), Max-CSP$({\cal F})$, is specified by a finite set of constraints ${\cal F} \subseteq \{[q]^k \to \{0,1\}\}$ for positive integers $q$ and $k$. An instance of the problem on $n$ variables is given by $m$ applications of constraints from ${\cal F}$ to subsequences of the $n$ ... more >>>

Vishwas Bhargava, Sumanta Ghosh

The orbit of an $n$-variate polynomial $f(\mathbf{x})$ over a field $\mathbb{F}$ is the set $\{f(A \mathbf{x} + b)\,\mid\, A\in \mathrm{GL}({n,\mathbb{F}})\mbox{ and }\mathbf{b} \in \mathbb{F}^n\}$, and the orbit of a polynomial class is the union of orbits of all the polynomials in it. In this paper, we give improved constructions of ... more >>>

Noah Fleming, Toniann Pitassi

This paper surveys the development of propositional proof complexity and the seminal contributions of Alasdair Urquhart. We focus on the central role of counting principles, and in particular Tseitin's graph tautologies, to most of the key advances in lower bounds in proof complexity. We reflect on a couple of key ... more >>>

Klim Efremenko, Gillat Kol, Raghuvansh Saxena

We study the error resilience of the message exchange task: Two parties, each holding a private input, want to exchange their inputs. However, the channel connecting them is governed by an adversary that may corrupt a constant fraction of the transmissions. What is the maximum fraction of corruptions that still ... more >>>

Yanyi Liu, Rafael Pass

We present the first natural $\NP$-complete problem whose average-case hardness w.r.t. the uniform distribution over instances implies the existence of one-way functions (OWF). In fact, we prove that the existence of OWFs is \emph{equivalent} to mild average-case hardness of this $\NP$-complete problem. The problem, which originated in the 1960s, is ... more >>>

Shuichi Hirahara

A long-standing and central open question in the theory of average-case complexity is to base average-case hardness of NP on worst-case hardness of NP. A frontier question along this line is to prove that PH is hard on average if UP requires (sub-)exponential worst-case complexity. The difficulty of resolving this ... more >>>

Hanlin Ren, Rahul Santhanam

A recent breakthrough of Liu and Pass (FOCS'20) shows that one-way functions exist if and only if the (polynomial-)time-bounded Kolmogorov complexity K^t is bounded-error hard on average to compute. In this paper, we strengthen this result and extend it to other complexity measures:

1. We show, perhaps surprisingly, that the ... more >>>

Yanyi Liu, Rafael Pass

Liu and Pass (FOCS'20) recently demonstrated an equivalence between the existence of one-way functions (OWFs) and mild average-case hardness of the time-bounded Kolmogorov complexity problem. In this work, we establish a similar equivalence but to a different form of time-bounded Kolmogorov Complexity---namely, Levin's notion of Kolmogorov Complexity---whose hardness is closely ... more >>>

Yanyi Liu, Rafael Pass

Let $\mktp[s]$ be the set of strings $x$ such that $K^t(x) \leq s(|x|)$, where $K^t(x)$ denotes the $t$-bounded Kolmogorov complexity of the truthtable described by $x$. Our main theorem shows that for an appropriate notion of mild average-case hardness, for every $\varepsilon>0$, polynomial $t(n) \geq (1+\varepsilon)n$, and every ``nice'' class ... more >>>

James Cook, Ian Mertz

We show that the Tree Evaluation Problem with alphabet size $k$ and height $h$ can be solved by branching programs of size $k^{O(h/\log h)} + 2^{O(h)}$. This answers a longstanding challenge of Cook et al. (2009) and gives the first general upper bound since the problem's inception.

more >>>Jan Krajicek

We study from the proof complexity perspective the (informal) proof search problem:

Is there an optimal way to search for propositional proofs?

We note that for any fixed proof system there exists a time-optimal proof search algorithm. Using classical proof complexity results about reflection principles we prove that a time-optimal ...
more >>>

Benny Applebaum, Oded Nir

A secret-sharing scheme allows to distribute a secret $s$ among $n$ parties such that only some predefined ``authorized'' sets of parties can reconstruct the secret, and all other ``unauthorized'' sets learn nothing about $s$.

The collection of authorized/unauthorized sets can be captured by a monotone function $f:\{0,1\}^n\rightarrow \{0,1\}$.

more >>>

Klim Efremenko, Gillat Kol, Raghuvansh Saxena

Interactive error correcting codes are codes that encode a two party communication protocol to an error-resilient protocol that succeeds even if a constant fraction of the communicated symbols are adversarially corrupted, at the cost of increasing the communication by a constant factor. What is the largest fraction of corruptions that ... more >>>

Marshall Ball, Alper Cakan, Tal Malkin

Motivated in part by applications in lattice-based cryptography, we initiate the study of the size of linear threshold (`$t$-out-of-$n$') secret-sharing where the linear reconstruction function is restricted to coefficients in $\{0,1\}$. We prove upper and lower bounds on the share size of such schemes. One ramification of our results is ... more >>>

Juraj Hromkovic

We call any consistent and sufficiently powerful formal theory that enables to algorithmically in polynomial time verify whether a text is a proof \textbf{efficiently verifiable mathematics} (ev-mathematics). We study the question whether nondeterminism is more powerful than determinism for polynomial time computations in the framework of ev-mathematics. Our main results ... more >>>

William Hoza

Three decades ago, Nisan constructed an explicit pseudorandom generator (PRG) that fools width-$n$ length-$n$ read-once branching programs (ROBPs) with error $\varepsilon$ and seed length $O(\log^2 n + \log n \cdot \log(1/\varepsilon))$ (Combinatorica 1992). Nisan's generator remains the best explicit PRG known for this important model of computation. However, a recent ... more >>>

Zander Kelley, Raghu Meka

A polynomial threshold function (PTF) $f:\mathbb{R}^n \rightarrow \mathbb{R}$ is a function of the form $f(x) = sign(p(x))$ where $p$ is a polynomial of degree at most $d$. PTFs are a classical and well-studied complexity class with applications across complexity theory, learning theory, approximation theory, quantum complexity and more. We address ... more >>>

Uma Girish, Avishay Tal, Kewen Wu

We prove that for every parity decision tree of depth $d$ on $n$ variables, the sum of absolute values of Fourier coefficients at level $\ell$ is at most $d^{\ell/2} \cdot O(\ell \cdot \log(n))^\ell$.

Our result is nearly tight for small values of $\ell$ and extends a previous Fourier bound ...
more >>>

Vishwas Bhargava, Shubhangi Saraf, Ilya Volkovich

We give new and efficient black-box reconstruction algorithms for some classes of depth-$3$ arithmetic circuits. As a consequence, we obtain the first efficient algorithm for computing the tensor rank and for finding the optimal tensor decomposition as a sum of rank-one tensors when then input is a {\it constant-rank} tensor. ... more >>>

Alexander Kulikov, Nikita Slezkin

Finding exact circuit size is a notorious optimization problem in practice. Whereas modern computers and algorithmic techniques allow to find a circuit of size seven in blink of an eye, it may take more than a week to search for a circuit of size thirteen. One of the reasons of ... more >>>

Peter Dixon, A. Pavan, N. V. Vinodchandran

The Acceptance Probability Estimation Problem (APEP) is to additively approximate the acceptance probability of a Boolean circuit. This problem admits a probabilistic approximation scheme. A central question is whether we can design a pseudodeterministic approximation algorithm for this problem: a probabilistic polynomial-time algorithm that outputs a canonical approximation with high ... more >>>

Dana Moshkovitz

We show that NP-hardness of approximating Boolean unique games on small set expanders can be amplified to the full Unique Games Conjecture on small set expanders.

The latter conjecture is known to imply hardness results for problems like Balanced-Separator, Minimum-Linear-Rearrangement and Small-Set-Expansion that are not known under the Unique ...
more >>>

Zhenjian Lu, Igor Carboni Oliveira

A probabilistic representation of a string $x \in \{0,1\}^n$ is given by the code of a randomized algorithm that outputs $x$ with high probability [Oliveira, ICALP 2019]. We employ probabilistic representations to establish the first unconditional Coding Theorem in time-bounded Kolmogorov complexity. More precisely, we show that if a distribution ... more >>>

Lijie Chen, Zhenjian Lu, Xin Lyu, Igor Carboni Oliveira

We develop a general framework that characterizes strong average-case lower bounds against circuit classes $\mathcal{C}$ contained in $\mathrm{NC}^1$, such as $\mathrm{AC}^0[\oplus]$ and $\mathrm{ACC}^0$. We apply this framework to show:

- Generic seed reduction: Pseudorandom generators (PRGs) against $\mathcal{C}$ of seed length $\leq n -1$ and error $\varepsilon(n) = n^{-\omega(1)}$ can ... more >>>

Zhenjian Lu, Igor Carboni Oliveira, Rahul Santhanam

We connect the study of pseudodeterministic algorithms to two major open problems about the structural complexity of $BPTIME$: proving hierarchy theorems and showing the existence of complete problems. Our main contributions can be summarised as follows.

1. A new pseudorandom generator and its consequences: We build on techniques developed to ... more >>>

Alessandro Chiesa, Fermi Ma, Nicholas Spooner, Mark Zhandry

We prove that Kilian's four-message succinct argument system is post-quantum secure in the standard model when instantiated with any probabilistically checkable proof and any collapsing hash function (which in turn exist based on the post-quantum hardness of Learning with Errors).

At the heart of our proof is a new ... more >>>

Prerona Chatterjee

The motivating question for this work is a long standing open problem, posed by Nisan (1991), regarding the relative powers of algebraic branching programs (ABPs) and formulas in the non-commutative setting. Even though the general question continues to remain open, we make some progress towards its resolution. To that effect, ... more >>>

Siddharth Bhandari, Prahladh Harsha, Mrinal Kumar, Madhu Sudan

In this work, we present an abstract framework for some algebraic error-correcting codes with the aim of capturing codes that are list-decodable to capacity, along with their decoding algorithm. In the polynomial ideal framework, a code is specified by some ideals in a polynomial ring, messages are polynomials and their ... more >>>

Robert Robere, Jeroen Zuiddam

We study the amortized circuit complexity of boolean functions.

Given a circuit model $\mathcal{F}$ and a boolean function $f : \{0,1\}^n \rightarrow \{0,1\}$, the $\mathcal{F}$-amortized circuit complexity is defined to be the size of the smallest circuit that outputs $m$ copies of $f$ (evaluated on the same input), ...
more >>>

Oded Goldreich

We study two notions that refers to asymmetric graphs, which we view as graphs having a unique ordering that can be reconstructed by looking at an unlabeled version of the graph.

A {\em local self-ordering} procedure for a graph $G$ is given oracle access to an arbitrary isomorphic copy of ... more >>>

Susanna de Rezende

We show that tree-like resolution is not automatable in time $n^{o(\log n)}$ unless ETH is false. This implies that, under ETH, the algorithm given by Beame and Pitassi (FOCS 1996) that automates tree-like resolution in time $n^{O(\log n)}$ is optimal. We also provide a simpler proof of the result of ... more >>>

Justin Holmgren, Alex Lombardi, Ron Rothblum

Shortly after the introduction of zero-knowledge proofs, Goldreich, Micali and Wigderson (CRYPTO '86) demonstrated their wide applicability by constructing zero-knowledge proofs for the NP-complete problem of graph 3-coloring. A long-standing open question has been whether parallel repetition of their protocol preserves zero knowledge. In this work, we answer this question ... more >>>

Vaibhav Krishan

We prove that all functions that have low degree torus polynomials approximating them with small error also have $MidBit^+$ circuits computing them. This serves as a partial converse to the result that all $ACC$ functions have low degree torus polynomials approximating them with small error, by Bhrushundi, Hosseini, Lovett and ... more >>>

Shuichi Hirahara, Rahul Ilango, Bruno Loff

How difficult is it to compute the communication complexity of a two-argument total Boolean function $f:[N]\times[N]\to\{0,1\}$, when it is given as an $N\times N$ binary matrix? In 2009, Kushilevitz and Weinreb showed that this problem is cryptographically hard, but it is still open whether it is NP-hard.

In this ... more >>>

Inbar Kaslasi, Ron Rothblum, Prashant Nalini Vasudevan

Suppose that a problem $\Pi$ has a statistical zero-knowledge (SZK) proof with communication complexity $m$. The question of batch verification for SZK asks whether one can prove that $k$ instances $x_1,\ldots,x_k$ all belong to $\Pi$ with a statistical zero-knowledge proof whose communication complexity is better than $k \cdot m$ (which ... more >>>

Anastasia Sofronova, Dmitry Sokolov

Restricted branching programs capture various complexity measures like space in Turing machines or length of proofs in proof systems. In this paper, we focus on the application in the proof complexity that was discovered by Lovasz et al. '95 who showed the equivalence between regular Resolution and read-once branching programs ... more >>>

Lijie Chen, Gillat Kol, Dmitry Paramonov, Raghuvansh Saxena, Zhao Song, Huacheng Yu

We give an almost quadratic $n^{2-o(1)}$ lower bound on the space consumption of any $o(\sqrt{\log n})$-pass streaming algorithm solving the (directed) $s$-$t$ reachability problem. This means that any such algorithm must essentially store the entire graph. As corollaries, we obtain almost quadratic space lower bounds for additional fundamental problems, including ... more >>>

Joshua Brakensiek, Venkatesan Guruswami, Sai Sandeep

Promise Constraint Satisfaction Problems (PCSPs) are a generalization of Constraint Satisfaction Problems (CSPs) where each predicate has a strong and a weak form and given a CSP instance, the objective is to distinguish if the strong form can be satisfied vs. even the weak form cannot be satisfied. Since their ... more >>>

Sivakanth Gopi, Venkatesan Guruswami

An $(n,r,h,a,q)$-Local Reconstruction Code is a linear code over $\mathbb{F}_q$ of length $n$, whose codeword symbols are partitioned into $n/r$ local groups each of size $r$. Each local group satisfies `$a$' local parity checks to recover from `$a$' erasures in that local group and there are further $h$ global parity ... more >>>

Mika Göös, Gilbert Maystre

We show that computing the majority of $n$ copies of a boolean function $g$ has randomised query complexity $\mathrm{R}(\mathrm{Maj} \circ g^n) = \Theta(n\cdot \bar{\mathrm{R}}_{1/n}(g))$. In fact, we show that to obtain a similar result for any composed function $f\circ g^n$, it suffices to prove a sufficiently strong form of the ... more >>>

Jiatu Li, Tianqi Yang

Proving circuit lower bounds has been an important but extremely hard problem for decades. Although one may show that almost every function $f:\mathbb{F}_2^n\to\mathbb{F}_2$ requires circuit of size $\Omega(2^n/n)$ by a simple counting argument, it remains unknown whether there is an explicit function (for example, a function in $NP$) not computable ... more >>>

Stefan Dantchev, Nicola Galesi, Abdul Ghani, Barnaby Martin

We prove logarithmic depth lower bounds in Stabbing Planes for the classes of combinatorial principles known as the Pigeonhole principle and the Tseitin contradictions. The depth lower bounds are new, obtained by giving almost linear length lower bounds which do not depend on the bit-size of the inequalities and in ... more >>>

Per Austrin, Kilian Risse

We study the complexity of proving that a sparse random regular graph on an odd number of vertices does not have a perfect matching, and related problems involving each vertex being matched some pre-specified number of times. We show that this requires proofs of degree $\Omega(n/\log n)$ in the Polynomial ... more >>>

Gil Cohen, Dean Doron, Oren Renard, Ori Sberlo, Amnon Ta-Shma

Weighted pseudorandom generators (WPRGs), introduced by Braverman, Cohen and Garg [BCG20], is a generalization of pseudorandom generators (PRGs) in which arbitrary real weights are considered rather than a probability mass. Braverman et al. constructed WPRGs against read once branching programs (ROBPs) with near-optimal dependence on the error parameter. Chattopadhyay and ... more >>>

Edward Pyne, Salil Vadhan

A recent paper of Braverman, Cohen, and Garg (STOC 2018) introduced the concept of a pseudorandom pseudodistribution generator (PRPG), which amounts to a pseudorandom generator (PRG) whose outputs are accompanied with real coefficients that scale the acceptance probabilities of any potential distinguisher. They gave an explicit construction of PRPGs for ... more >>>

Dean Doron, Raghu Meka, Omer Reingold, Avishay Tal, Salil Vadhan

We study monotone branching programs, wherein the states at each time step can be ordered so that edges with the same labels never cross each other. Equivalently, for each fixed input, the transition functions are a monotone function of the state.

We prove that constant-width monotone branching programs of ... more >>>

Timothy Gowers, Emanuele Viola

We initiate a systematic study of mixing in non-quasirandom groups.

Let $A$ and $B$ be two independent, high-entropy distributions over

a group $G$. We show that the product distribution $AB$ is statistically

close to the distribution $F(AB)$ for several choices of $G$ and

$F$, including:

(1) $G$ is the affine ... more >>>

Shalev Ben-David, Mika Göös, Siddhartha Jain, Robin Kothari

We exhibit an unambiguous $k$-DNF formula that requires CNF width $\tilde{\Omega}(k^{1.5})$. Our construction is inspired by the board game Hex and it is vastly simpler than previous ones, which achieved at best an exponent of $1.22$. Our result is known to imply several other improved separations in query and communication ... more >>>

Chandan Saha, Bhargav Thankey

The orbit of an $n$-variate polynomial $f(\mathbf{x})$ over a field $\mathbb{F}$ is the set $\mathrm{orb}(f) := \{f(A\mathbf{x}+\mathbf{b}) : A \in \mathrm{GL}(n,\mathbb{F}) \ \mathrm{and} \ \mathbf{b} \in \mathbb{F}^n\}$. This paper studies explicit hitting sets for the orbits of polynomials computable by certain well-studied circuit classes. This version of the hitting set ... more >>>

Dori Medini, Amir Shpilka

In this paper we study polynomials in VP$_e$ (polynomial-sized formulas) and in $\Sigma\Pi\Sigma$ (polynomial-size depth-$3$ circuits) whose orbits, under the action of the affine group GL$^{aff}_n({\mathbb F})$, are dense in their ambient class. We construct hitting sets and interpolating sets for these orbits as well as give reconstruction algorithms.

As ... more >>>

Srinivasan Arunachalam, Penghui Yao

In a recent work, O'Donnell, Servedio and Tan (STOC 2019) gave explicit pseudorandom generators (PRGs) for arbitrary $m$-facet polytopes in $n$ variables with seed length poly-logarithmic in $m,n$, concluding a sequence of works in the last decade, that was started by Diakonikolas, Gopalan, Jaiswal, Servedio, Viola (SICOMP 2010) and Meka, ... more >>>

Noah Fleming, Mika Göös, Russell Impagliazzo, Toniann Pitassi, Robert Robere, Li-Yang Tan, Avi Wigderson

The Stabbing Planes proof system was introduced to model the reasoning carried out in practical mixed integer programming solvers. As a proof system, it is powerful enough to simulate Cutting Planes and to refute the Tseitin formulas -- certain unsatisfiable systems of linear equations mod 2 -- which are canonical ... more >>>

Chi-Ning Chou, Alexander Golovnev, Madhu Sudan, Santhoshini Velusamy

A Boolean constraint satisfaction problem (CSP), Max-CSP$(f)$, is a maximization problem specified by a constraint $f:\{-1,1\}^k\to\{0,1\}$. An instance of the problem consists of $m$ constraint applications on $n$ Boolean variables, where each constraint application applies the constraint to $k$ literals chosen from the $n$ variables and their negations. The goal ... more >>>

Eric Allender, John Gouwar, Shuichi Hirahara, Caleb Robelle

A version of time-bounded Kolmogorov complexity, denoted KT, has received attention in the past several years, due to its close connection to circuit complexity and to the Minimum Circuit Size Problem MCSP. Essentially all results about the complexity of MCSP hold also for MKTP (the problem of computing the KT ... more >>>

Eric Allender, Mahdi Cheraghchi, Dimitrios Myrisiotis, Harsha Tirumala, Ilya Volkovich

One-way functions (OWFs) are central objects of study in cryptography and computational complexity theory. In a seminal work, Liu and Pass (FOCS 2020) proved that the average-case hardness of computing time-bounded Kolmogorov complexity is equivalent to the existence of OWFs. It remained an open problem to establish such an equivalence ... more >>>

Akash Kumar, C. Seshadhri, Andrew Stolman

Consider the family of bounded degree graphs in any minor-closed family (such as planar graphs). Let d be the degree bound and n be the number of vertices of such a graph. Graphs in these classes have hyperfinite decompositions, where, for a sufficiently small ? > 0, one removes

?dn ...
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Sai Sandeep

Multidimensional packing problems generalize the classical packing problems such as Bin Packing, Multiprocessor Scheduling by allowing the jobs to be $d$-dimensional vectors. While the approximability of the scalar problems is well understood, there has been a significant gap between the approximation algorithms and the hardness results for the multidimensional variants. ... more >>>

Susanna de Rezende, Jakob Nordström, Marc Vinyals

We obtain the first true size-space trade-offs for the cutting planes proof system, where the upper bounds hold for size and total space for derivations with constant-size coefficients, and the lower bounds apply to length and formula space (i.e., number of inequalities in memory) even for derivations with exponentially large ... more >>>

Anindya De, Elchanan Mossel, Joe Neeman

A natural problem in high-dimensional inference is to decide if a classifier $f:\mathbb{R}^n \rightarrow \{-1,1\}$ depends on a small number of linear directions of its input data. Call a function $g: \mathbb{R}^n \rightarrow \{-1,1\}$, a linear $k$-junta if it is completely determined by some $k$-dimensional subspace of the input space. ... more >>>

Vishnu Iyer, Avishay Tal, Michael Whitmeyer

Leveraging tools of De, Mossel, and Neeman [FOCS, 2019], we show two different results pertaining to the tolerant testing of juntas. Given black-box access to a Boolean function $f:\{\pm1\}^{n} \to \{\pm1\}$ we give a poly$(k, \frac{1}{\varepsilon})$ query algorithm that distinguishes between functions that are $\gamma$-close to $k$-juntas and $(\gamma+\varepsilon)$-far from ... more >>>

Lijie Chen, Xin Lyu

In this work we prove that there is a function $f \in \textrm{E}^\textrm{NP}$ such that, for every sufficiently large $n$ and $d = \sqrt{n}/\log n$, $f_n$ ($f$ restricted to $n$-bit inputs) cannot be $(1/2 + 2^{-d})$-approximated by $\textrm{F}_2$-polynomials of degree $d$. We also observe that a minor improvement ...
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Pooya Hatami, William Hoza, Avishay Tal, Roei Tell

We present new constructions of pseudorandom generators (PRGs) for two of the most widely-studied non-uniform circuit classes in complexity theory. Our main result is a construction of the first non-trivial PRG for linear threshold (LTF) circuits of arbitrary constant depth and super-linear size. This PRG fools circuits with depth $d\in\mathbb{N}$ ... more >>>

Klim Efremenko, Gillat Kol, Dmitry Paramonov, Raghuvansh Saxena

We study the $n$-party noisy broadcast channel with a constant fraction of malicious parties. Specifically, we assume that each non-malicious party holds an input bit, and communicates with the others in order to learn the input bits of all non-malicious parties. In each communication round, one of the parties broadcasts ... more >>>