English
Related papers

Related papers: Optimal lower bounds for quantum automata and rand…

200 papers

A word $w$ is called synchronizing (recurrent, reset, magic, directable) word of deterministic finite automaton (DFA) if $w$ sends all states of the automaton to a unique state. In 1964 Jan \v{C}erny found a sequence of n-state complete DFA…

Discrete Mathematics · Computer Science 2014-03-24 A. N. Trahtman

Random access codes are a type of communication task that is widely used in quantum information science. The optimal average success probability that can be achieved through classical strategies is known for any random access code. However,…

Quantum Physics · Physics 2025-02-27 Máté Farkas , Nikolai Miklin , Armin Tavakoli

We prove a very general lower bound technique for quantum and randomized query complexity, that is easy to prove as well as to apply. To achieve this, we introduce the use of Kolmogorov complexity to query complexity. Our technique…

Quantum Physics · Physics 2007-05-23 Sophie Laplante , Frederic Magniez

The quantum approximate optimization algorithm, also known in its generalization as the quantum alternating operator ansatz, (QAOA) is a heuristic hybrid quantum-classical algorithm for finding high-quality approximate solutions to…

Multi-letter {\it quantum finite automata} (QFAs) were a new one-way QFA model proposed recently by Belovs, Rosmanis, and Smotrovs (LNCS, Vol. 4588, Springer, Berlin, 2007, pp. 60-71), and they showed that multi-letter QFAs can accept with…

Computational Complexity · Computer Science 2010-03-10 Daowen Qiu , Sheng Yu

A quantum finite-state automaton (QFA) is a theoretical model designed to simulate the evolution of a quantum system with finite memory in response to sequential input strings. We define the language of a QFA as the set of strings that lead…

Computation and Language · Computer Science 2024-07-04 SeungYeop Baik , Sicheol Sung , Yo-Sub Han

The 2-way quantum finite automaton introduced by Kondacs and Watrous can accept non-regular languages with bounded error in polynomial time. If we restrict the head of the automaton to moving classically and to moving only in one direction,…

Quantum Physics · Physics 2007-05-23 Alex Brodsky , Nicholas Pippenger

In this paper, we first introduce a lower bound technique for the state complexity of transformations of automata. Namely we suggest first considering the class of full automata in lower bound analysis, and later reducing the size of the…

Logic in Computer Science · Computer Science 2015-07-01 Qiqi Yan

The ambiguity of a nondeterministic finite automaton (NFA) N for input size n is the maximal number of accepting computations of N for an input of size n. For all k, r 2 N we construct languages Lr,k which can be recognized by NFA's with…

Formal Languages and Automata Theory · Computer Science 2009-03-02 Juraj Hromkovic , Georg Schnitger

In the present work, we lay out a new theory showing that all automata can always be co-lexicographically partially ordered, and an intrinsic measure of their complexity can be defined and effectively determined, namely, the minimum width…

Formal Languages and Automata Theory · Computer Science 2023-05-04 Nicola Cotumaccio , Giovanna D'Agostino , Alberto Policriti , Nicola Prezza

We establish a lower bound of $\Omega{(\sqrt{n})}$ on the bounded-error quantum query complexity of read-once Boolean functions, providing evidence for the conjecture that $\Omega(\sqrt{D(f)})$ is a lower bound for all Boolean functions.…

Quantum Physics · Physics 2007-05-23 Howard Barnum , Michael Saks

We show that any quantum algorithm deciding whether an input function $f$ from $[n]$ to $[n]$ is 2-to-1 or almost 2-to-1 requires $\Theta(n)$ queries to $f$. The same lower bound holds for determining whether or not a function $f$ from…

Computational Complexity · Computer Science 2012-02-01 Paul Beame , Widad Machmouchi

It was conjectured by \v{C}ern\'y in 1964, that a synchronizing DFA on $n$ states always has a synchronizing word of length at most $(n-1)^2$, and he gave a sequence of DFAs for which this bound is reached. Until now a full analysis of all…

Formal Languages and Automata Theory · Computer Science 2018-09-18 Michiel de Bondt , Henk Don , Hans Zantema

Unambiguous non-deterministic finite automata have intermediate expressive power and succinctness between deterministic and non-deterministic automata. It has been conjectured that every unambiguous non-deterministic one-way finite…

Computational Complexity · Computer Science 2018-02-15 Michael Raskin

"Quantitative languages are extension of boolean languages that assign to each word a real number. Mean-payoff automata are finite automata with numerical weights on transitions that assign to each infinite path the long-run average of the…

Logic in Computer Science · Computer Science 2012-05-20 Yaron Velner

In this thesis, we introduce a new quantum Turing machine (QTM) model that supports general quantum operators, together with its pushdown, counter, and finite automaton variants, and examine the computational power of classical and quantum…

Computational Complexity · Computer Science 2011-02-03 Abuzer Yakaryilmaz

In this paper we study a generalized model named one-way general quantum finite automata} (1gQFA), in which each symbol in the input alphabet induces a trace-preserving quantum operation, instead of a unitary transformation. Two different…

Quantum Physics · Physics 2010-10-26 Lvzhou Li , Daowen Qiu , Xiangfu Zou , Lvjun Li , Lihua Wu , Paulo Mateus

We refine a uniform algebraic approach for deriving upper bounds on reset thresholds of synchronizing automata. We express the condition that an automaton is synchronizing in terms of linear algebra, and obtain upper bounds for the reset…

Formal Languages and Automata Theory · Computer Science 2015-12-21 Mikhail Berlinkov , Marek Szykuła

Given a Probabilistic Finite Automata (PFA), a set of states S, and an error threshold e > 0, our algorithm approximates the infimum probability (quantifying over all infinite words) that the automata reaches S. Our result contrasts with…

Logic in Computer Science · Computer Science 2010-09-21 Sergio Giro

A locally testable language L is a language with the property that for some non negative integer k, called the order or the level of local testable, whether or not a word u in the language L depends on (1) the prefix and the suffix of the…

Formal Languages and Automata Theory · Computer Science 2020-11-13 A. N. Trahtman