# Questions tagged [heuristics]

The heuristics tag has no usage guidance.

39
questions

**4**

votes

**1**answer

171 views

### Idea behind Carleson's theorem modern proof “intitial reductions”

I'm having troubles to understand the philosophy behind the modern proof of Carleson's theorem. For convenience, let me state precisely what I am asking for.
For any $f \in L^2(\mathbb{R})$, let $\...

**0**

votes

**0**answers

20 views

### Heuristics for the heaviest eulerian subgraph

Given a complete symmetric graph with $n=2k$ vertices and positive edgeweights, are there any better algorithms for determining the heaviest eulerian subgraph than this one that strives for finding ...

**-1**

votes

**1**answer

42 views

### What is known about iterated matching as a TSP heuristic

A fairly wellknown heuristic for TSP that is based on matching is described in the 2003 paper Match twice and stitch: a new TSP tour construction heuristic by Andrew B. Kahng and Sherief Reda.
Its ...

**0**

votes

**0**answers

32 views

### Reasons for inapplicability of complete induction to tour expansion

It is known that tour expansion is a rather poor heuristic for generating short Hamilton cycles even in the planar Euclidean case. That comes as a surprise when learning of that for the first time.
...

**1**

vote

**0**answers

22 views

### Complexity of tour-expansion heuristic for the planar Euclidean TSP

This is a followup question to this one: Computational Geometric Aspects of Greedy Tour Expansion.
Assume that the candidate point, whose insertion into current incurs the least tour-length increase, ...

**3**

votes

**1**answer

224 views

### Is there a clear criterion or rule about when one can use the heuristic given by Cramér random model for prime numbers?

I don't know if I have misunderstood the information from the section about the heuristic related to Cramér's conjecture and the known facts about Maier's theorem, from the Wikipedia Cramér's ...

**0**

votes

**0**answers

14 views

### Generating sparse vertex-biconnected planar spanners of complete weighted graphs

Given a simple complete graph $\pmb{G}$ with weighted edges, what can be said about the following strategy of generating biconnected sparse planar spanners:
Start: $\pmb{S}\ :=\ $a lightweight vertex ...

**3**

votes

**1**answer

152 views

### How can we justify the use of Example 5,4 (of Cohen, Lenstra) assuming their heuristics

In these days, I'm studying Cohen-Lenstra heuristics to understand the paper of Rene Schoof "Class Numbers of Real Cyclotomic Fields of Prime Conductor".
On page 932 of Schoof's paper, there is a ...

**3**

votes

**0**answers

64 views

### Matching of two weighted graphs allowing one-to-many mapping

I am looking for a heuristic for a graph matching problem as follows.
Given two graphs: $A$ (consisting of nodes $a_i$) and $B$ (consisting of nodes $b_i$). Typically the size of $B$ is larger than ...

**4**

votes

**1**answer

420 views

### Does multiplication increase entropy?

Does multiplication increase entropy?
The Shannon entropy of a number $k$ in binary digits is defined as
$$ H = -\log(\frac{a}{l})\cdot\frac{a}{l} - \log(1-\frac{a}{l})\cdot (1-\frac{a}{l})$$
where $...

**1**

vote

**0**answers

166 views

### Heuristic for lower bounding the time for integer factorization?

I am posting this question here in hope that someone finds this heuristic useful, and maybe someone with more experience will make use of this:
As @GerryMyerson suggested here is a statement of what ...

**0**

votes

**1**answer

60 views

### Can time-scale calculus be used to derive a counterpart theorem of discrete-time dynamic systems directly from continuos-time dynamics systems?

From what I read of time-scale calculus literature, most results of continuous-time and discrete-time systems can be generalized to arbitrary time-scales by considering the generalized derivative ...

**0**

votes

**0**answers

26 views

### Generating Biconnected Graphs from Spanning Trees

Background of my question is an idea for generating an initial subtour for general symmetric TSPs:
Add to a MST a set of edges with minimal weight sum, that renders the resulting graph free of ...

**3**

votes

**2**answers

604 views

### Heuristics behind the Circle problem?

Is there a heuristic argument behind the exponent in the circle problem? The problem that I am referring to is the following: Consider a circle of radius $R$ centered at the origin in the plane and ...

**55**

votes

**16**answers

5k views

### What are examples of books which teach the practice of mathematics?

One may classify the types of mathematics books written for students into two groups: books which merely teach mathematics (i.e., they present theorems and proofs, ready-made, as it were) and those ...

**5**

votes

**0**answers

490 views

### why do we mainly integrate with respect to martingales?

Although my resarch focuses on PDEs (optimal transport, these days), I am currently trying to learn stochastic calculus and integration. I am just beginning in this topics, but I was wondering: why do ...

**1**

vote

**1**answer

113 views

### Computational Geometric Aspects of Greedy Tour Expansion

Has the following problem already been investigated from the Computational Geometry point of view and what are the results regarding worst case complexity?
Given
a finite set $\mathcal{P}...

**1**

vote

**0**answers

97 views

### Heuristics for this “subset” traveling salesman problem

Are there any known heuristics for the following variation of the traveling salesman problem: given $n$ sets of points $S_1,\dots,S_n$, and $n$ integers $k_i$ such that $k_i \leq |S_i|$, find the ...

**3**

votes

**2**answers

170 views

### (How) do Better TSP Heuristics help in Answering the $NP=P$ Question?

This question is motivated by my impression, that finding better heuristics for the TSP problem (or any other $NP$-complete problem) is "only" of practical interest, but doesn't provide any progress ...

**5**

votes

**0**answers

225 views

### The set of numbers $a+b$ such that $ma^2+nb^2$ is prime

Conjecture:
If $m,n$ are coprime it exist a minimal natural number $N_{mn}$ such
that:
$\{a+b>N_{mn}\mid a,b\in\mathbb N^+\wedge ma^2+nb^2\in\mathbb P_{>2}\} = \{ k > N_{mn} \mid \...

**2**

votes

**1**answer

126 views

### Worst Case Region for a Convex Hull Heuristic

I am currently implementing a heuristic algorithm for planar convex hulls hand would like to know, for which kind of strictly convex region it exhibits worst performance.
I know that there are many ...

**2**

votes

**1**answer

147 views

### Heuristics for counting degrees of freedom

I have recently learned about the representation theorem for isotropic,
linear operators, which says the following:
Defintion:
Let $M_n$ be the vector space of $n \times n$ real matrices. We say a ...

**1**

vote

**0**answers

33 views

### Performance guarantee of RLF [closed]

I cannot manage to find the performance guarantee of the Recursive Largest First (RLF) algorithm for approximating the chromatic number of a graph.
I know DSATUR has a $\mathcal{O}(n)$ guarantee, ...

**4**

votes

**1**answer

596 views

### Heuristic probabilistic argument for the Navier-Stokes existence and smoothness conjecture

The Collatz Conjecture is a famous conjecture that has never been proven; nevertheless, there exists a simple heuristic probabilistic argument which supports its truth - in Wikipedia's words, "If one ...

**70**

votes

**4**answers

4k views

### What are reasons to believe that e is not a period?

In their 2001 paper defining periods, Kontsevich and Zagier (pdf) without further comment state that $e$ is conjecturally not a period while many other numbers showing up naturally (conjecturally) are....

**2**

votes

**2**answers

542 views

### Categories with binary relations as objects

For the category of functions, pairs of functions making commutative diagrams are the canonical morphisms $\alpha:f\rightarrow g$. For binary relations there is an alternative, to consider the ...

**7**

votes

**1**answer

384 views

### Cohen-Lenstra heuristics for totally complex fields

If a number field $K$ is a Galois extension of $\mathbb{Q}$, and $G = \operatorname{Gal}(K/\mathbb{Q})$, then the class group of $K$ is a $\mathbb{Z}[G]$-module, and since $N = \sum_{g \in G} g$ acts ...

**1**

vote

**0**answers

137 views

### Reduce a Combinatorial problem

It is given n sets with k vectors. (k is element-wise positive or zero)
Choose one vector of each set so that the biggest element of the sum of the chosen vectors is minimal.
What i also know but is ...

**1**

vote

**1**answer

63 views

### Heuristic for choosing n-vectors from n-sets

my given problem is:
choose n-vectors from n-sets (one vector from each set) so that the biggest element in the sum of the chosen vectors is minimal. Unfortunately the problem is NP-hard. So I'm ...

**31**

votes

**18**answers

5k views

### Non-rigorous reasoning in rigorous mathematics

I was wondering what role non-rigorous, heuristic type arguments play in rigorous math. Are there examples of rigorous, formal proofs in which a non-rigorous reasoning still plays a central part?
...

**1**

vote

**0**answers

177 views

### unfolding as resolution

Has anyone described 'unfolding' as used in mathematical physics (e.g. on-shell AND off-shell) as analogous to a resolution in algebra - higher derivatives are unfolded in terms of new variables?

**4**

votes

**2**answers

262 views

### Formula in common: How to search for same/similar equations in other knowledge domains?

Hi people
In a recent presentation by Sedgewick, he recounts in 1977 Flajolet noticed that they had a formula in common, both in different domains (see slide 4 in http://www.cs.princeton.edu/~rs/...

**12**

votes

**0**answers

764 views

### What is the intuition for $\mathbb{Q}^{ab}$ having cohomological dimension $1$?

I frequently talk to people who think of finite fields as arithmetic analogs of punctured discs. This makes some sense: the absolute Galois group of a finite field is the profinite completion of $\...

**9**

votes

**2**answers

2k views

### Defining the slowest divergent series

This question might seem too fuzzy, and if so, I will be happy to withdraw it. Until then, here it is:
I know that a method of slowing a divergent series of positive reals is to replace the $n$-th ...

**8**

votes

**0**answers

731 views

### Two different ways to count Mersenne Primes

Hi there, the motivation for this question is to better understand the heuristics of Mersenne primes, and I was motivated by the recent questions (Mersenne quasi-primes) and (Primes in generalized ...

**4**

votes

**1**answer

466 views

### class groups of unramified cyclic p-extensions of imaginary quadratic fields

Let $K$ be an imaginary quadratic number field with $p$-Sylow-class group $A(K)$ and $L/K$ be an unramified cyclic extension of $K$ of degree $p$ ($p$ prime). Then I am looking for heuristics on
$...

**9**

votes

**3**answers

2k views

### Groupoids vs Pseudogroups

(Warning: I'm not an expert in the topic) Let's work in a "geometric" category, for example the category $\mathfrak{Diff}$ of "manifolds" (without the requirements of connectedness and second ...

**2**

votes

**1**answer

201 views

### Possible semantics for categorical co-constness

In category theory a morphism is constant IIF it is absorbing (for left composition).
That is a morphism $k$ from $k:A\rightarrow B$ is constant
if an only if for any two parrallel (same domain and ...

**35**

votes

**6**answers

70k views

### Fourier vs Laplace transforms

In solving a linear system, when would I use a Fourier transform versus a Laplace transform? I am not a mathematician, so the little intuition I have tells me that it could be related to the boundary ...