Imperial College London

ProfessorMartinLiebeck

Faculty of Natural SciencesDepartment of Mathematics

Head of Pure Mathematics Section/Prof of Pure Mathematics
 
 
 
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Contact

 

+44 (0)20 7594 8490m.liebeck Website

 
 
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Location

 

665Huxley BuildingSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Guralnick:2019:10.1007/s11856-018-1794-x,
author = {Guralnick, R and Liebeck, MW},
doi = {10.1007/s11856-018-1794-x},
journal = {Israel Journal of Mathematics},
pages = {181--191},
title = {Permutation representations of nonsplit extensions involving alternating groups},
url = {http://dx.doi.org/10.1007/s11856-018-1794-x},
volume = {229},
year = {2019}
}

RIS format (EndNote, RefMan)

TY  - JOUR
AB - L. Babai has shown that a faithful permutation representation of a nonsplit extension of a group by an alternating group Ak must have degree at least k2(12−o(1)), and has asked how sharp this lower bound is. We prove that Babai’s bound is sharp (up to a constant factor), by showing that there are such nonsplit extensions that have faithful permutation representations of degree 32k(k−1). We also reprove Babai’s quadratic lower bound with the constant 1/2 improved to 1 (by completely different methods).
AU - Guralnick,R
AU - Liebeck,MW
DO - 10.1007/s11856-018-1794-x
EP - 191
PY - 2019///
SN - 0021-2172
SP - 181
TI - Permutation representations of nonsplit extensions involving alternating groups
T2 - Israel Journal of Mathematics
UR - http://dx.doi.org/10.1007/s11856-018-1794-x
UR - http://hdl.handle.net/10044/1/58417
VL - 229
ER -