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REPORTS > KEYWORD > NP-COMPLETENESS:
Reports tagged with NP-completeness:
TR95-024 | 23rd May 1995
Mihir Bellare, Oded Goldreich, Madhu Sudan

Free bits, PCP and Non-Approximability - Towards tight results

Revisions: 4

This paper continues the investigation of the connection between proof
systems and approximation. The emphasis is on proving ``tight''
non-approximability results via consideration of measures like the
``free bit complexity'' and the ``amortized free bit complexity'' of
proof systems.

The first part of the paper presents a collection of new ... more >>>


TR97-047 | 20th October 1997
Miklos Ajtai

The Shortest Vector Problem in L_2 is NP-hard for Randomized Reductions.

Revisions: 1

We show that the shortest vector problem in lattices
with L_2 norm is NP-hard for randomized reductions. Moreover we
also show that there is a positive absolute constant c, so that to
find a vector which is longer than the shortest non-zero vector by no
more than a factor of ... more >>>


TR97-058 | 2nd December 1997
Oded Goldreich

Notes on Levin's Theory of Average-Case Complexity.


In 1984, Leonid Levin has initiated a theory of average-case complexity.
We provide an exposition of the basic definitions suggested by Levin,
and discuss some of the considerations underlying these definitions.

more >>>

TR98-008 | 15th January 1998
Sanjeev Arora, Carsten Lund, Rajeev Motwani, Madhu Sudan, Mario Szegedy

Proof verification and the hardness of approximation problems.


We show that every language in NP has a probablistic verifier
that checks membership proofs for it using
logarithmic number of random bits and by examining a
<em> constant </em> number of bits in the proof.
If a string is in the language, then there exists a proof ... more >>>


TR98-034 | 23rd June 1998
Venkatesan Guruswami, Daniel Lewin and Madhu Sudan, Luca Trevisan

A tight characterization of NP with 3 query PCPs


It is known that there exists a PCP characterization of NP
where the verifier makes 3 queries and has a {\em one-sided}
error that is bounded away from 1; and also that 2 queries
do not suffice for such a characterization. Thus PCPs with
3 ... more >>>


TR98-040 | 24th July 1998
Madhu Sudan, Luca Trevisan

Probabilistically checkable proofs with low amortized query complexity

The error probability of Probabilistically Checkable Proof (PCP)
systems can be made exponentially small in the number of queries
by using sequential repetition. In this paper we are interested
in determining the precise rate at which the error goes down in
an optimal protocol, and we make substantial progress toward ... more >>>


TR99-029 | 31st August 1999
Ilya Dumer, Daniele Micciancio, Madhu Sudan

Hardness of approximating the minimum distance of a linear code

We show that the minimum distance of a linear code (or
equivalently, the weight of the lightest codeword) is
not approximable to within any constant factor in random polynomial
time (RP), unless NP equals RP.
Under the stronger assumption that NP is not contained in RQP
(random ... more >>>


TR99-045 | 16th November 1999
Valentine Kabanets, Jin-Yi Cai

Circuit Minimization Problem

We study the complexity of the circuit minimization problem:
given the truth table of a Boolean function f and a parameter s, decide
whether f can be realized by a Boolean circuit of size at most s. We argue
why this problem is unlikely to be in P (or ... more >>>


TR01-032 | 3rd April 2001
A. Pavan, Alan L. Selman

Separation of NP-completeness Notions

We use hypotheses of structural complexity theory to separate various
NP-completeness notions. In particular, we introduce an hypothesis from which we describe a set in NP that is Turing complete but not truth-table complete. We provide fairly thorough analyses of the hypotheses that we introduce. Unlike previous approaches, we ... more >>>


TR03-049 | 25th June 2003
Piotr Berman, Marek Karpinski, Alexander D. Scott

Approximation Hardness of Short Symmetric Instances of MAX-3SAT

We prove approximation hardness of short symmetric instances
of MAX-3SAT in which each literal occurs exactly twice, and
each clause is exactly of size 3. We display also an explicit
approximation lower bound for that problem. The bound two on
the number ... more >>>


TR04-035 | 10th April 2004
Scott Contini, Ernie Croot, Igor E. Shparlinski

Complexity of Inverting the Euler Function

We present an algorithm to invert the Euler function $\varphi(m)$. The algorithm, for a given integer $n\ge 1$, in polynomial time ``on average'', finds theset $\Psi(n)$ of all solutions $m$ to the equation $\varphi(m) =n$. In fact, in the worst case the set $\Psi(n)$ is exponentially large and cannot be ... more >>>


TR04-075 | 21st July 2004
Michael Schmitt

Some dichotomy theorems for neural learning problems

The computational complexity of learning from binary examples is
investigated for linear threshold neurons. We introduce
combinatorial measures that create classes of infinitely many
learning problems with sample restrictions. We analyze how the
complexity of these problems depends on the values for the measures.
... more >>>


TR06-039 | 28th February 2006
John Hitchcock, A. Pavan

Comparing Reductions to NP-Complete Sets

Under the assumption that NP does not have p-measure 0, we
investigate reductions to NP-complete sets and prove the following:

- Adaptive reductions are more powerful than nonadaptive
reductions: there is a problem that is Turing-complete for NP but
not truth-table-complete.

- Strong nondeterministic reductions are more powerful ... more >>>


TR06-069 | 11th May 2006
Christian Gla├čer, Alan L. Selman, Stephen Travers, Klaus W. Wagner

The Complexity of Unions of Disjoint Sets

This paper is motivated by the open question
whether the union of two disjoint NP-complete sets always is
NP-complete. We discover that such unions retain
much of the complexity of their single components. More precisely,
they are complete with respect to more general reducibilities.

more >>>

TR06-146 | 30th September 2006
Christoph Buchheim, Peter J Cameron, Taoyang Wu

On the Subgroup Distance Problem

We investigate the computational complexity of finding an element of
a permutation group~$H\subseteq S_n$ with a minimal distance to a
given~$\pi\in S_n$, for different metrics on~$S_n$. We assume
that~$H$ is given by a set of generators, such that the problem
cannot be solved in polynomial time ... more >>>


TR14-126 | 9th October 2014
Debasis Mandal, A. Pavan, Rajeswari Venugopalan

Separating Cook Completeness from Karp-Levin Completeness under a Worst-Case Hardness Hypothesis

We show that there is a language that is Turing complete for NP but not many-one complete for NP, under a {\em worst-case} hardness hypothesis. Our hypothesis asserts the existence of a non-deterministic, double-exponential time machine that runs in time $O(2^{2^{n^c}})$ (for some $c > 1$) accepting $\Sigma^*$ whose accepting ... more >>>


TR14-164 | 30th November 2014
Cody Murray, Ryan Williams

On the (Non) NP-Hardness of Computing Circuit Complexity

The Minimum Circuit Size Problem (MCSP) is: given the truth table of a Boolean function $f$ and a size parameter $k$, is the circuit complexity of $f$ at most $k$? This is the definitive problem of circuit synthesis, and it has been studied since the 1950s. Unlike many problems of ... more >>>


TR14-167 | 11th November 2014
Beate Bollig

On the Minimization of (Complete) Ordered Binary Decision Diagrams

Ordered binary decision diagrams (OBDDs) are a popular data structure for Boolean functions.
Some applications work with a restricted variant called complete OBDDs
which is strongly related to nonuniform deterministic finite automata.
One of its complexity measures is the width which has been investigated
in several areas in computer science ... more >>>


TR15-198 | 30th November 2015
Shuichi Hirahara, Osamu Watanabe

Limits of Minimum Circuit Size Problem as Oracle

Revisions: 1

The Minimum Circuit Size Problem (MCSP) is known to be hard for statistical zero knowledge via a BPP-reduction (Allender and Das, 2014), whereas establishing NP-hardness of MCSP via a polynomial-time many-one reduction is difficult (Murray and Williams, 2015) in the sense that it implies ZPP $\neq$ EXP, which is a ... more >>>


TR16-012 | 21st January 2016
John Hitchcock, Hadi Shafei

Autoreducibility of NP-Complete Sets

We study the polynomial-time autoreducibility of NP-complete sets and obtain separations under strong hypotheses for NP. Assuming there is a p-generic set in NP, we show the following:

- For every $k \geq 2$, there is a $k$-T-complete set for NP that is $k$-T autoreducible, but is not $k$-tt autoreducible ... more >>>




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