A copy of this work was available on the public web and has been preserved in the Wayback Machine. The capture dates from 2020; you can also visit the original URL.
The file type is application/pdf
.
Filters
Intervals of permutation class growth rates
[article]
2015
arXiv
pre-print
We prove that the set of growth rates of permutation classes includes an infinite sequence of intervals whose infimum is θ_B≈2.35526, and that it also contains every value at least λ_B≈2.35698. ...
These results improve on a theorem of Vatter, who determined that there are permutation classes of every growth rate at least λ_A≈2.48187. ...
He would also like to thank Vince, Robert Brignall and two referees for reading earlier drafts of this paper; their feedback resulted in significant improvements to its presentation. S.D.G. ...
arXiv:1410.3679v2
fatcat:7i5poymeqvg35dyjv3pcbj7rym
Intervals of Permutation Class Growth Rates
2017
Combinatorica
We prove that the set of growth rates of permutation classes includes an infinite sequence of intervals whose infimum is θB ≈ 2.35526, and that it also contains every value at least λB ≈ 2.35698. ...
These results improve on a theorem of Vatter, who determined that there are permutation classes of every growth rate at least λA ≈ 2.48187. ...
He would also like to thank Vince, Robert Brignall and two referees for reading earlier drafts of this paper; their feedback resulted in significant improvements to its presentation. Soli Deo gloria! ...
doi:10.1007/s00493-016-3349-2
fatcat:fzh4oiwozrcvrpfgopkoc3enni
PERMUTATION CLASSES OF EVERY GROWTH RATE ABOVE 2.48188
2009
Mathematika
We prove that there are permutation classes (hereditary properties of permutations) of every growth rate (Stanley-Wilf limit) at least \lambda \approx 2.48187, the unique real root of x^5-2x^4-2x^2-2x- ...
1, thereby establishing a conjecture of Albert and Linton. ...
permutation classes of growth rate κ. ...
doi:10.1112/s0025579309000503
fatcat:hk73x5eixzb2fdaahin4wotc7a
Large infinite antichains of permutations
[article]
2012
arXiv
pre-print
We prove the existence and detail the construction of infinite antichains with arbitrarily large growth rates. ...
Infinite antichains of permutations have long been used to construct interesting permutation classes and counterexamples. ...
was stronger than the statement that every upper growth rate of a permutation class is algebraic. ...
arXiv:1212.3346v2
fatcat:ep5aggpnb5filaugpghfbjazm4
Growth rates of permutation classes: categorization up to the uncountability threshold
[article]
2019
arXiv
pre-print
We conclude by refuting a suggestion of Klazar, showing that ξ is an accumulation point from above of growth rates of finitely based permutation classes. ...
In the antecedent paper to this it was established that there is an algebraic number ξ≈ 2.30522 such that while there are uncountably many growth rates of permutation classes arbitrarily close to ξ, there ...
There are uncountably many permutation classes of growth rate κ. ...
arXiv:1605.04289v3
fatcat:fj5tomw7jfdfdmaxed4iryq7u4
Permutation classes
[article]
2015
arXiv
pre-print
This is a survey on permutation classes for the upcoming book Handbook of Enumerative Combinatorics. ...
This chapter has greatly benefited by the comments, corrections, and suggestions of the referee as well as those of Michael Albert, David Bevan, Jonathan Bloom, Robert Brignall, Cheyne Homberger, Vít Jelínek ...
The upper growth rate of a wpo permutation class is equal to the greatest upper growth rate of its atomic subclasses. ...
arXiv:1409.5159v3
fatcat:epgv2blhfjd6flmjcdqmf66dka
Some open problems on permutation patterns
[article]
2013
arXiv
pre-print
Other subjects treated are the Möbius function, topological properties and other algebraic aspects of the poset of permutations, ordered by containment, and also the study of growth rates of permutation ...
classes, which are containment closed subsets of this poset. ...
Acknowledgements I am deeply grateful to Vince Vatter, who provided invaluable help, in particular with the section on growth rates. ...
arXiv:1210.7320v2
fatcat:stgw6rpxerbtbdztalhbp3ft2q
Permutation patterns: basic definitions and notation
[article]
2015
arXiv
pre-print
A brief presentation of basic definitions and notation used in permutation patterns research. ...
A generating function is rational if it is the ratio of two polynomials. A generating function F(z) is algebraic if it can be defined as the root of a polynomial equation. ...
Hence, the upper growth rate and lower growth rate of a class C are defined to be gr(C) = lim sup n→∞ |C n | 1/n and gr(C) = lim inf n→∞ |C n | 1/n . ...
arXiv:1506.06673v1
fatcat:4oheockukrerflrqn32hjm5mvm
Growth rates of permutation classes: from countable to uncountable
[article]
2019
arXiv
pre-print
We establish that there is an algebraic number ξ≈ 2.30522 such that while there are uncountably many growth rates of permutation classes arbitrarily close to ξ, there are only countably many less than ...
The classification of growth rates up to ξ is completed in a subsequent paper. ...
1 Every upper growth rate of a permutation class is the growth rate of a sum closed class. ...
arXiv:1605.04297v3
fatcat:fbvrvghpzzdepo4geb42yipmmm
Growth rates for subclasses of Av(321)
[article]
2009
arXiv
pre-print
Pattern classes which avoid 321 and other patterns are shown to have the same growth rates as similar (but strictly larger) classes obtained by adding articulation points to any or all of the other patterns ...
The method of proof is to show that the elements of the latter classes can be represented as bounded merges of elements of the original class, and that the bounded merge construction does not change growth ...
For the remainder of this paper we will only be using the second of these estimates; that the growth rate of a bounded merge of two permutation classes is the maximum of their individual growth rates. ...
arXiv:0903.1999v2
fatcat:csjjzq7mang6falfeay2g6536m
Growth Rates for Subclasses of $\mathrm{Av}(321)$
2010
Electronic Journal of Combinatorics
Pattern classes which avoid $321$ and other patterns are shown to have the same growth rates as similar (but strictly larger) classes obtained by adding articulation points to any or all of the other patterns ...
The method of proof is to show that the elements of the latter classes can be represented as bounded merges of elements of the original class, and that the bounded merge construction does not change growth ...
Growth rates offer a way of approximating the number of permutations of a given length in a pattern class. ...
doi:10.37236/413
fatcat:gifr6gaacrbqhd4tpbiazlejku
On Permutation Pattern Classes with Two Restrictions Only
2007
Annals of Combinatorics
Permutation pattern classes that are defined by avoiding two permutations only and which contain only finitely many simple permutations are characterized and their growth rates are determined. ...
For this reason K is called the growth rate of the class. ...
In this paper we shall show how to find the growth rate of a 3-parameter family of pattern classes. ...
doi:10.1007/s00026-007-0320-3
fatcat:iaome2wbxnd53mmbxql6ola5fe
Growing at a Perfect Speed
2009
Combinatorics, probability & computing
and sal@dcs.st-and.ac.uk A collection of permutation classes is exhibited whose growth rates form a perfect set, thereby refuting some conjectures of Balogh, Bollobás and Morris. ...
The set of growth rates of permutation classes includes some interval (λ, ∞). In fact, we suspect that the least such λ, if it exists, is not very large. ...
A simple maximization exercise then shows that the growth rate of this new class is equal to the sum of the growth rates of A and of B. ...
doi:10.1017/s0963548309009699
fatcat:uxa5niy33nf47exhftfec23kuu
Small permutation classes
2011
Proceedings of the London Mathematical Society
countably many permutation classes of growth rate (Stanley-Wilf limit) less than κ but uncountably many permutation classes of growth rate κ, answering a question of Klazar. ...
We go on to completely characterize the possible sub-κ growth rates of permutation classes, answering a question of Kaiser and Klazar. ...
Is there a (upper, lower, proper) growth rate of a permutation class that is not achieved by a sum closed permutation class? The existence of growth rates. ...
doi:10.1112/plms/pdr017
fatcat:3vqwu775tzd27kzfoo4mvrpbfi
Inflations of geometric grid classes of permutations
2014
Israel Journal of Mathematics
This bound is tight as there are permutation classes with growth rate κ which have nonrational generating functions. ...
In particular, these are the two main tools in the recent classification of permutation classes of growth rate less than κ « 2.20557 (a specific algebraic integer at which infinite antichains first appear ...
classes of growth rate less than κ « 2.20557. ...
doi:10.1007/s11856-014-1098-8
fatcat:incyrf4zivfudpgb5pgtior6i4
« Previous
Showing results 1 — 15 out of 26,886 results