All reports by Author Robert Robere:

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TR24-010
| 19th January 2024
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Noah Fleming, Stefan Grosser, Toniann Pitassi, Robert Robere#### Black-Box PPP is not Turing-Closed

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TR23-068
| 10th May 2023
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Ben Davis, Robert Robere#### Colourful TFNP and Propositional Proofs

Revisions: 1

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TR20-099
| 6th July 2020
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Susanna de Rezende, Or Meir, Jakob Nordström, Toniann Pitassi, Robert Robere#### KRW Composition Theorems via Lifting

Revisions: 1

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TR20-064
| 2nd May 2020
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Mika Göös, Jakob Nordström, Toniann Pitassi, Robert Robere, Dmitry Sokolov, Susanna de Rezende#### Automating Algebraic Proof Systems is NP-Hard

Revisions: 2

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TR20-001
| 31st December 2019
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Or Meir, Jakob Nordström, Robert Robere, Susanna de Rezende#### Nullstellensatz Size-Degree Trade-offs from Reversible Pebbling

Revisions: 2

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TR19-186
| 31st December 2019
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Or Meir, Jakob Nordström, Toniann Pitassi, Robert Robere, Susanna de Rezende#### Lifting with Simple Gadgets and Applications to Circuit and Proof Complexity

Revisions: 4

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TR16-188
| 21st November 2016
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Toniann Pitassi, Robert Robere#### Strongly Exponential Lower Bounds for Monotone Computation

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TR13-054
| 4th April 2013
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Yuval Filmus, Toniann Pitassi, Robert Robere, Stephen A. Cook#### Average Case Lower Bounds for Monotone Switching Networks

Revisions: 1

Noah Fleming, Stefan Grosser, Toniann Pitassi, Robert Robere

The complexity class PPP contains all total search problems many-one reducible to the PIGEON problem, where we are given a succinct encoding of a function mapping n+1 pigeons to n holes, and must output two pigeons that collide in a hole. PPP is one of the “original five” syntactically-defined subclasses ... more >>>

Ben Davis, Robert Robere

Recent work has shown that many of the standard TFNP classes — such as PLS, PPADS, PPAD, SOPL, and EOPL — have corresponding proof systems in propositional proof complexity, in the sense that a total search problem is in the class if and only if the totality of the problem ... more >>>

Susanna de Rezende, Or Meir, Jakob Nordström, Toniann Pitassi, Robert Robere

One of the major open problems in complexity theory is proving super-logarithmic lower bounds on the depth of circuits (i.e., $\mathbf{P}\not\subseteq\mathbf{NC}^1$). Karchmer, Raz, and Wigderson (Computational Complexity 5(3/4), 1995) suggested to approach this problem by proving that depth complexity behaves “as expected” with respect to the composition of functions $f ... more >>>

Mika Göös, Jakob Nordström, Toniann Pitassi, Robert Robere, Dmitry Sokolov, Susanna de Rezende

We show that algebraic proofs are hard to find: Given an unsatisfiable CNF formula $F$, it is NP-hard to find a refutation of $F$ in the Nullstellensatz, Polynomial Calculus, or Sherali--Adams proof systems in time polynomial in the size of the shortest such refutation. Our work extends, and gives a ... more >>>

Or Meir, Jakob Nordström, Robert Robere, Susanna de Rezende

We establish an exactly tight relation between reversible pebblings of graphs and Nullstellensatz refutations of pebbling formulas, showing that a graph $G$ can be reversibly pebbled in time $t$ and space $s$ if and only if there is a Nullstellensatz refutation of the pebbling formula over $G$ in size $t+1$ ... more >>>

Or Meir, Jakob Nordström, Toniann Pitassi, Robert Robere, Susanna de Rezende

We significantly strengthen and generalize the theorem lifting Nullstellensatz degree to monotone span program size by Pitassi and Robere (2018) so that it works for any gadget with high enough rank, in particular, for useful gadgets such as equality and greater-than. We apply our generalized theorem to solve two open ... more >>>

Toniann Pitassi, Robert Robere

For a universal constant $\alpha > 0$, we prove size lower bounds of $2^{\alpha N}$ for computing an explicit monotone function in NP in the following models of computation: monotone formulas, monotone switching networks, monotone span programs, and monotone comparator circuits, where $N$ is the number of variables of the ... more >>>

Yuval Filmus, Toniann Pitassi, Robert Robere, Stephen A. Cook

An approximate computation of a Boolean function by a circuit or switching network is a computation which computes the function correctly on the majority of the inputs (rather than on all inputs). Besides being interesting in their own right, lower bounds for approximate computation have proved useful in many subareas ... more >>>