Questions tagged [computer-science]
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36 questions from the last 365 days
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Graph classes which have small edge k-cuts
I am interested in graph classes that have the following property: There exists a function $f(k)$ such that for every graph $G$ in the class, for every choice of $k$ vertices $v_1, \ldots, v_k$ in the ...
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2
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Shifting an irrational binary sequence
Let $\newcommand{\tn}{\{0,1\}^\mathbb{N}}\tn$ be the collection of all infinite binary sequences. For $s\in\tn$ and $k\in\mathbb{N}$ let the left-shift of $s$ by $k$ positions, $\ell_k(s)\in \tn$, be ...
- 48.9k
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Is the set of generalized Fermat triples computable?
Is $\;\big\{(a,b,c)\in\mathbb{N}^3: \big(\exists m,n,\ell \in (\mathbb{N}\setminus\{0,1,2\})\big): a^m + b^n= c^\ell\big\}\;$ computable?
- 48.9k
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Computer program for free restricted Lie polynomial
I am conducting numerical experiments involving the Gröbner–Shirshov Basis for restricted Lie algebras. At each step of the computation, I need to work with restricted Lie polynomials. Specifically, I ...
- 1,013
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References: rigorous algorithms for elementary computations in base-b with complexity estimates
Definitions/Notation: Fix positive integers $b$ and $M$. Consider the set of real numbers which can be exactly expressed with $2M+1$ coefficients in base $b$, defined by
$$\mathcal{X}(b,M):=\{x\in \...
- 5,405
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0
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120
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References on P vs NP under various axiomatic systems
I am teaching algorithms and theory of computation this semester and had the opportunity to dig a bit into the details of one way functions and the P vs NP problem.
This problem has resisted attacks ...
- 31
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Computing all roots of a function with square-root terms
Given $3n$ positive numbers $a_1, \ldots, a_n$, $b_1, \ldots, b_n$, and $x_1, \ldots, x_n$, we are given a function
$$f(x) = \sum_{i = 1}^n \frac{a_i}{\sqrt{(x - x_i)^2 + b_i}}.$$
Can we find all the ...
- 11
1
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0
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30
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M-char reduction inverse Theorem [closed]
I need a bit of help finishing this theorem I believe it to be true. First, set $\mathcal{B} = \{A, B, \dots, Z\}$ to be the set of capital letters in base 64, and define $\mathcal{A}_m$ as the set of ...
- 317
1
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1
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Probability distribution on Python-dictionary-like objects?
I would like to examine information-theoretical properties of random variables that take as values objects which are akin to dictionaries in the Python programing language.
That is, each sample of the ...
- 11
3
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0
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Lower Bound of Solutions to P=NP?
Do we at least know that simulating polynomial time non-deterministic Turing machines requires more than a linear slowdown? That is, do we know there is some non-deterministic Turing machine with ...
- 3,029
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Is this variant of post correspondence problem undecidable?
The post correspondence problem, as defined by wikipedia, is undecidable. The problem is defined as follows.
Let $A$ be an alphabet with at least two symbols. The input of the problem consists of ...
- 21
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0
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78
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On binary constraints defined by vanishing of bivariate polynomials modulo $n$ [duplicate]
In an answer here
Dima Pasechnik showed that constraints of the form $x_i x_j + a_{ij}x_i + b_{ij}x_j + c_{ij}$ are efficiently solvable modulo $2$ using Groebner basis.
In comments he suggested that ...
- 25.4k
3
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1
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315
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About Shor's quantum algorithm
I know very little about quantum computing, and I've been trying to understand Shor's algorithm for the factorization of an integer $N$. I'm following Computational Complexity — a modern approach by ...
- 2,287
1
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0
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Multipoint evaluation in Lagrange basis on subset smaller than degree
Setup. Let $\mathbb{F}$ be a finite field with a multiplicative subgroup $E = \{e_1, \dots, e_k\}$ of order $k$. Given a list $y = y_1, \dots, y_k\in \mathbb{F}$ let $p$ be the unique polynomial of ...
2
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0
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122
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What do we know about efficiently finding a solution to a system of multivariate polynomials over finite fields?
Consider the following (NP-complete) problem:
Given a system of polynomials $f_1, f_2, \ldots, f_m \in \mathbb{F}_q[x_1, x_2, \ldots, x_n]$ of total degree at most $d$, find an $\mathbb{F}_q$-rational ...
- 121
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106
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How can I transform every graph into one with constant out-degree?
I am working on my master thesis and try to implement a new shortest path algorithm from the following paper: https://arxiv.org/abs/2203.03456
In some of the functions (for example ScaleDown), ...
1
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1
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91
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Probabilistic 2D cellular automata with memory lifetime increasing like $e^{L^2}$
Consider 2-state probabilistic cellular automata on an $L\times L$ torus square lattice which has the all-$0$ and all-$1$ configurations as fixed points, thinking of something similar to Toom's rule ...
- 3,001
4
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1
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341
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rank of an integer valued matrix
I make some numerical experiments, involving rank of integer valued matrices of the size about $14\times 24$. As the matrix is integer valued, theoretically there should be no room for errors. However ...
- 728
2
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173
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NP-hardness of a string transformation problem with k templates
Given strings $x$ and $y$, a template length $l$, and a maximum number of different templates $k$, the task is to determine if it's possible to convert $x$ into $y$ using no more than $k$ different ...
- 21
2
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graphs which have polynomial bounded number of cycles
How does the graph class defined as those graphs which have polynomial (or quasi polynomial) bounded number of cycles look? (in number of vertices)
I suspect it will rather non-interesting as ...
- 129
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Polynomial-time quantum algorithms for lattice problems (GapSVP, SIVP, LWE)
The author of a recent preprint claims to have found polynomial-time quantum algorithms for solving the following lattice problems: the Decisional Shortest Vector Problem (GapSVP), the Shortest ...
- 157
1
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2
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198
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Topology of directed graph $G$ with non-singular adjacency matrix
Given a directed graph $G$ with non-singular adjacency matrix,
Q. Is there a directed
subgraph $H$ in $G$ that can be represented as the union of disjoint cycles such that $H$ contains all nodes of $...
- 4,058
1
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1
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168
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Permutation graph with insert-and-shift
Motivation. I am working with a database software that allows
you to sort the fields of any given table in the following
peculiar way. Suppose your fields are numbered $1,\ldots, 18$.
Next to every ...
- 48.9k
0
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2
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96
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Isometric path cover number of the 2 dimensional grid graph
I am looking for a proof of the fact that at least $2n/3$ isometric paths (i.e. shortest paths between the end points) are required to cover the vertices of the $n\times n$ grid graph (i.e. Cartesian ...
- 1,305
12
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2
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Soft question: Deep learning and higher categories
Recently, I have stumbled upon certain articles and lecture videos that use category theory to explain certain aspects of machine learning or deep learning (e.g. Cats for AI and the paper An enriched ...
- 231
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0
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A small lemma on cache resets (Bloom filters in particular)
Assume a fixed set of message $D$ and an associated distribution for selecting each message $d_i$ such that the total probability $\sum_{i \in D} d_i = 1$. We create a cache with $M$ bits and $k$ ...
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0
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83
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Interpreting multiple property tests at different values of $\epsilon,\delta$ [closed]
I am doing some work in the area of Property Testing, as in Goldreich, Goldwasser, and Ron (2008) or the textbook Introduction to Property Testing (Goldreich). In this framework, I run a test to see ...
- 171
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95
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What does the computation of irrationality and transcendentality via a fancy implementation of analytic Markov's property look like?
Proofs that various real numbers are not rational or not algebraic tend to be constructively valid as is. Examples include the proofs that $\sqrt 2$ and $\log_2(3)$ are not rational and that $e$ is ...
- 6,353
1
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0
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Set functions satisfying if $f(X) \le f(Y)$ and $Z \cap (X \cup Y) = \emptyset$, then $f(X \cup Z) \le f(Y \cup Z)$
I am investigating set functions $f : 2^\Omega \to \mathbb{N}$ satisfying the following two properties:
(monotone) For all $X, Y \subset \Omega$, if $X \subseteq Y$, then $f(X) \le f(Y)$.
(property ...
- 151
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When is a container a monad?
The category of polynomial functors on Set is equivalent to the category of containers.
We have a prescription for when a container is a comonad.
There are a few other questions that come to mind. ...
- 1,313
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1
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Application of Resultant in Computer Algebra [closed]
Can you guys give me some application of resultant in Computer Algebra, it will be amazing if you guys can give me some paper or book to read more. Thanks so much
35
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3
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Using Busy Beavers to prove conjectures
I've been pondering some stuff on Shtetl Optimized where Yedidia and Aaronson construct Turing machines that will only halt if (e.g.) the Riemann Hypothesis is false, or Goldbach's conjecture is false....
- 483
3
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0
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Computational complexity of exact computation of the doubling dimension
Given a finite metric space $X$, the doubling constant of $X$ is the smallest integer $k$ such that any ball of arbitrary radius $r$ can be covered by at most $k$ balls of radius $r/2$. The doubling ...
3
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1
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308
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Root finding algorithm for an analytic function
Given an analytic function $f(x)$. What is the best algorithm to find roots on the interval $[a,b]$ inside the radius of convergence> What is its complexity with respect to the length of input of ...
- 81
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1
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Robustness of doubling dimension to small perturbations
Let $M$ be a metric space. Then the doubling dimension of $M$, denoted $\dim M$, is defined to be the minimum value $k$ such that every ball in $M$ of radius $r$ can be covered by at most $2^k$ balls ...