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6
votes
1answer
95 views

Lower bound on prefix code lengths

For a prefix code $C:\{0,1\}^*\to\{0,1\}^*$, define $f(n)$ as the length of the longest encoding of a number with up to $n$ bits: $$ f(n)=\max_{|k|\le n}\left|C(k)\right|. $$ (Note that by taking ...
3
votes
0answers
100 views

Fast Approximation Algorithms for Covering Design

The covering design problem is as follows: We are given a universe $\mathcal{U}$ of size $n$. By $C(n,k,l)$ we denote the smallest cardinality of any set system $\mathcal{A} \subset 2^\mathcal{U}$ ...
10
votes
1answer
213 views

Introduction to probabilistic automata

Where can I find an introduction to probabilistic automata and what they recognize (certain functions from words to $[0,1]$)? Is there a standard term for such functions which are recognized by ...
6
votes
2answers
209 views

Implementing “Internal” Languages

One of the most practical consequences of the "Curry-Howard-Lambek" correspondence is that the syntax of many lambda-calucli/logics can be used to perform constructions in a sufficiently structured ...
-4
votes
0answers
88 views

Automated theorem proving for Euclid's “Infinity of Primes”

This file from Thousands of Problems for Theorem Proving(TPTP) has the setup for proving Euclid's theorem for Infinity of Primes (along some references to some papers). It also has a list of axioms, ...
10
votes
1answer
148 views

Is there a survey of the field of quantum automata?

I'm looking for a survey paper of the important concepts in the field of Quantum Automata. I've found Quantum Automata Theory -- A Review by Hirvensalo, but it sounds too succinct to grasp the topic. ...
13
votes
1answer
669 views

Rabin's “degree of difficulty of computing a function, and a partial ordering of recursive sets”

I am looking for: Michael O. Rabin, "Degree of difficulty of computing a function, and a partial ordering of recursive sets", Hebrew University, Jerusalem, 1960 Summary: “We attempt to measure ...
13
votes
1answer
310 views

Novel proof of pumping lemma for regular languages

Let $\mathcal{L}$ be the family of all languages over $\Sigma$ satisfying the pumping property of regular languages. Namely: for each $L\in\mathcal{L}$, there is an $N\in\mathbb{N}$ s.t. every word ...
7
votes
0answers
108 views

Kleinberg Rubinfeld Short Paths in Expander Graphs for Hypergraphs

In the 1996 paper "Short Paths in Expander Graphs" by Kleinberg and Rubinfeld, the authors show a randomized polynomial-time algorithm for finding an embedding of a graph $H$ into a graph $G$, if $G$ ...
8
votes
3answers
243 views

Convergence theorem for Genetic Programming?

Genetic Programming (GP) is stochastic algorithm, there has been early attempts to explain its convergence with the Schmea Theorem (Holland 1975) for Genetic Algorithm adapted for GP such as (Koza ...
13
votes
1answer
310 views

Expected minimum influence of a random Boolean function $f\colon\{-1,1\}^n \to \{-1,1\}$

For a Boolean function $f\colon\{-1,1\}^n \to \{-1,1\}$, the influence of the $i$th variable is defined as $$ \operatorname{Inf}_i[f] \stackrel{\rm def}{=} \Pr_{x\sim\{-1,1\}^n}[ f(x) \neq f(x^{\oplus ...
5
votes
0answers
134 views

Machine learning algorithms on hypergrap models

Graphical models are a very useful tool with many applications, whereby a joint distribution of a set of random variables is modeled using only pairwise dependencies between the variables, and two ...
8
votes
1answer
117 views

Tree-decomposition with clique interfaces

Let $G=(V,E)$ be a finite undirected graph. A tree decomposition $(T,\lambda)$ of $G$ is a tree $T$ with labeling function $\lambda : T \to 2^{V}$ such that: For every edge $\{v_1,v_2\} \in E$, ...
8
votes
0answers
102 views

Recognition of a primitive root

Adleman and McCurley published a paper in 1994 called "Open problems in number theoretic complexity, II" (http://ww.cstheory.com/papers/open.ps.gz) Problem 18 of this list of open problems is about ...
8
votes
1answer
143 views

Complexity of the edge-disjoint cycle covers

I am interested in decompositions of a directed graph $G=(V,E)$ into non-intersecting Eulerian subgraphs $G_i=(V_i, E_i)$. I want to find the decomposition that covers the largest number of edges. I ...
4
votes
1answer
114 views

Problems still “hard” in the SMP/Referee model with shared randomness?

In the referee (SMP: Simultaneous Message Passing) model introduced by Yao (see e.g. [1]), Alice and Bob have respectively inputs $x\in X$ and $y\in Y$, and wish to communicate with a third-party, the ...
9
votes
0answers
103 views

“k-Swap SAT” problem

I would like to know if the following NP-complete problem has a name and has been studied: Input: Given a CNF formula $\varphi$ on $n$ variables, a truth assignment $\sigma:[n] \to \{T,F\}$ and an ...
2
votes
0answers
23 views

Stochastic optimization with erroneous oracles

I am interested in a class of optimization problems of which we know that the input variable is first subjected to noise $\xi$ before entering the data-producing process $f$. I write the objective in ...
3
votes
0answers
96 views

Hashtable vs cache-oblivious [closed]

I'd like to know more about real performances of data structures, in particular two families attract my interests: hash tables cache oblivious My researches didn't find any "comprehensive" (let me ...
8
votes
3answers
382 views

How to design concurrent data structures?

I previously asked this question on Programmers.SE, without success. I'm looking for written learning resources on how to design concurrent data structures. I'm more interested in the design process ...
17
votes
0answers
495 views

Deeper look at Algorithmica?

Russell Impagliazzo published "A Personal View of Average-Case Complexity" (preprint) back in 1995. He presented five possible worlds we could be living in, depending on how P and NP were related. The ...
10
votes
1answer
188 views

Complexity of digraph homomorphism to an oriented cycle

Given a fixed directed graph (digraph) $D$, the $D$-COLORING decision problem asks whether an input digraph $G$ has a homomorphism to $D$. (A homomorphism of $G$ to $D$ is a mapping $f$ of $V(G)$ to ...
4
votes
2answers
107 views

Ordered-file maintenance

I am studying the Advanced Data Structures material and I'd like to implement the Ordered-file maintenance data structure. I have few questions in order to start. The papers rely on a static view, ...
9
votes
0answers
306 views

Upper Bound on Number of $n \times n$ Boolean matrices of Boolean rank at most $k$

An $n \times n$ Boolean matrix $B$ has Boolean rank $k$ if there exist matrices $L \in \{0,1\}^{n \times k}$ and $R \in \{0,1\}^{k \times n}$, s.t. $B = L \circ R$. Here $\circ$ denotes the Boolean ...
6
votes
2answers
222 views

Local Graph Isomorphism to construct Global Graph Isomorphism

Does there exist a Graph Isomorphism Algorithm that uses Local Isomorphism to construct a Global Isomorphism? For example, two graphs are given, say, $H, G$. it is asked to determine whether $G\simeq ...
7
votes
1answer
125 views

A word anticorrespondence problem

A problem instance is a finite list of 4-tuples $(\alpha_1, u_1, v_1, \beta_1), ..., (\alpha_N, u_N, v_N, \beta_N)$, where $\alpha_i, \beta_i \in X$ come from a finite set, and each $u_i,v_i \in A^*$ ...
1
vote
1answer
72 views

Normal form for deterministic (sub)sequential transducers with letter-by-letter outputs

For a project I'm working on, it would seem useful to have a normal form for deterministic (sub)sequential transducers in which the set of states, $Q$, is partitioned into states, $r \in Q_R$, that ...
1
vote
0answers
90 views

Minimizing a monotone submodular function under a cardinality constraint

I would like to know what the status of the following question is: Given query access to a non-decreasing, non-negative submodular function $f\colon 2^{[n]} \to \mathbb{R}$ and a parameter $0 ...
5
votes
0answers
129 views

The evaluation problem for AC$^0_d$ formulas is in FO

Let $d \in \mathbb{N}$ be arbitrary. Let $\mathsf{AC^0_d}$-Eval be the following promise problem: Input: A depth $d$ formula $\varphi(x)$ and a binary string $a$. Output: $\varphi(a)$ I am looking ...
5
votes
0answers
105 views

Is there an approximation algorithm for MAX k DOUBLE SET COVER?

Given a set system $(X,\mathcal S)$, let us say that a subset $\mathcal C\subseteq \mathcal S$ doubly covers a vertex $x$ in $X$ if $x$ is contained in at least two sets of $\mathcal C$. Let us define ...
1
vote
3answers
226 views

List of complexity classes closed under complement

Is there a list of 'natural' complexity classes closed under complement? Some that I could think of are P, ZPP, BPP, NP $\cap$ co-NP, PH, PP and PSPACE but surely there are others. Wikipedia and the ...
7
votes
1answer
231 views

Inexact labelled binary tree matching

Does anyone recognise the following problems? Do they have names? Are they hard? If we were looking for an exact match (0 mismatches), these would be solvable in polynomial time (using e.g. standard ...
4
votes
2answers
200 views

Partition graph into 2 or more claw-free subgraphs

Is it NP-hard to partition the vertex set of graph G into k subsets so that they induce k claw-free subgraphs of G?
11
votes
6answers
2k views

Book for self study of algorithms in group theory

I am a math major interested on TCS. I want to self-study the algorithms, and complexity of them for solving the group theoretical problems like find order of elements, coset enumeration, find ...
4
votes
1answer
144 views

Can we confirm that 2-SAT can indeed be transformed into Horn-SAT in this manner?

In the question, Translating SAT to HornSAT, Martin Seymour gives a method due to Joshua Grochow. It transforms 2-SAT into Horn-SAT, by creating a variable for every possible 2-SAT clause. Then, if ...
7
votes
1answer
223 views

Major open problems on polynomial kernel (non) existence

We are not able to settle the (non) existence of a polynomial kernel for a parametrized combinatorial NP-complete problem (we also tried to apply some recent lower bound techniques to prove the non ...
3
votes
1answer
129 views

How to evaluate and compare the performance of algorithms in practice?

Let $A$ be a heuristic algorithm for problem $Q$. I want to evaluate the performance of my algorithm in a specific practical environment and compare it to other algorithms. Is there a rigorous ...
0
votes
1answer
87 views

Lossless Compression Books

I am intrigued by compression techniques and I'd like some recommendations about books to study, specifically, on lossless compression algorithms and data structures. I don't know if there is a ...
1
vote
0answers
116 views

Vertices adjacent to Exterior region of a Planar Graph(Algorithm)

Problem: I am looking for an algorithm which finds all vertices that are adjacent to exterior region of a planar graph(For a planar graph, any region=face can be considered as the exterior region ...
1
vote
0answers
157 views

Tree decomposition for DAGs

Tree decompositions and treewidth are a standard way to measure how close an undirected graph is to a tree. I am studying decompositions of directed acyclic graphs (DAGs), and have come to define them ...
14
votes
2answers
1k views

Status quo of category theory and monads in theoretical computer science research?

Background. I am a bachelor student who is interested in research related to category theory, monads and Haskell, and I want to find a topic for my bachelor’s thesis in that area. I have looked at ...
14
votes
2answers
240 views

Recent TCS publications with philosophical aspects

Many computer science publications from the 1950s and 1960s contain fascinating philosophical speculations on the nature of the mind and the meaning of information in relation to the physical world. ...
10
votes
0answers
87 views

Is it #P-hard to compute the number of antichains of a distributive lattice?

An antichain of a poset $(P, <)$ is a subset of pairwise incomparable elements, namely, a subset $A \subseteq P$ such that there are no $x, y \in A$ with $x < y$. By a result of Provan and Ball, ...
9
votes
0answers
58 views

historical question: earliest description of beta-normal terms together with “neutral” terms in lambda calculus?

A bit of "folklore" in lambda calculus is the idea of characterizing the class of $\beta$-normal terms inductively as a syntactic category ($R$) defined in mutual induction with an auxiliary syntactic ...
6
votes
1answer
255 views

NP-hardness of coloring uniform hypergraphs

Since a $2$-uniform hypergraphs are just graphs. The problem of deciding if $2$-uniform is $k$-colorable for $k=1,2$ is easy, and NP-hard for $k \geq 3$ colors. This is well know and I have seen ...
2
votes
0answers
92 views

A variant of the tiling problem

A classic tiling problem with Wang tiles has the form: Given $n$ tiles $T=\{t_1,...,t_n\}$ and some constraints $H,V\subseteq T\times T$, is there a way to tile a $w\times h$ rectangular grid with ...
7
votes
1answer
187 views

Two DFA intersection emptiness connections to SETH & L vs P

(re "fine grained complexity") Wehar has proved that Two DFA intersection emptiness in $O(n^{2-\epsilon})$ time → SETH false. does anyone see any particular key proof difficulty, challenge, ...
0
votes
0answers
90 views

Complexity classes for problems that can be solved only from the length of the input

A tally language is a language on an alphabet with only one symbol. One can define complexity classes for tally languages, such as $P_1$ (the tally languages that can be decided in polynomial time). ...
6
votes
1answer
156 views

Quantum Hardness of Approximating Lattice Problems

A common claim in lattice-based cryptography is that cryptosystems based on the Learning with Errors ($\mathsf{LWE}$) problem are hard to break (for a per-system definition of "break") for quantum ...
48
votes
7answers
3k views

For which problems in P is it easier to verify the result than to find it?

For (search versions) of NP-complete problems, verifying a solution is clearly easier than finding it, since the verification can be done in polynomial time, while finding a witness takes (probably) ...