Hostname: page-component-78c5997874-4rdpn Total loading time: 0 Render date: 2024-11-13T11:08:00.060Z Has data issue: false hasContentIssue false

Order-Invariant Measures on Fixed Causal Sets

Published online by Cambridge University Press:  19 January 2012

GRAHAM BRIGHTWELL
Affiliation:
Department of Mathematics, London School of Economics and Political Science, Houghton Street, London WC2A 2AE, UK (e-mail: g.r.brightwell@lse.ac.uk)
MALWINA LUCZAK
Affiliation:
School of Mathematics and Statistics, University of Sheffield, Hicks Building, Hounsfield Road, Sheffield S3 7RH, UK (e-mail: m.luczak@sheffield.ac.uk)

Abstract

A causal set is a countably infinite poset in which every element is above finitely many others; causal sets are exactly the posets that have a linear extension with the order-type of the natural numbers; we call such a linear extension a natural extension. We study probability measures on the set of natural extensions of a causal set, especially those measures having the property of order-invariance: if we condition on the set of the bottom k elements of the natural extension, each feasible ordering among these k elements is equally likely. We give sufficient conditions for the existence and uniqueness of an order-invariant measure on the set of natural extensions of a causal set.

Type
Paper
Copyright
Copyright © Cambridge University Press 2012

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

[1]Aldous, D. and Diaconis, P. (1999) Longest increasing subsequences: From patience sorting to the Baik–Deift–Johansson theorem. Bull. Amer. Math. Soc. 36 413432.CrossRefGoogle Scholar
[2]Billingsley, P. (1999) Convergence of Probability Measures, Wiley.CrossRefGoogle Scholar
[3]Bovier, A. (2006) Statistical Mechanics of Disordered Systems, Cambridge University Press.CrossRefGoogle Scholar
[4]Brightwell, G. R. (1988) Linear extensions of infinite posets. Discrete Math. 70 113136.CrossRefGoogle Scholar
[5]Brightwell, G. R. (1989) Semiorders and the 1/3–2/3 conjecture. Order 5 369380.CrossRefGoogle Scholar
[6]Brightwell, G. R. (1999) Balanced pairs in partial orders. Discrete Math. 201 2552.CrossRefGoogle Scholar
[7]Brightwell, G. R. and Georgiou, N. (2010) Continuum limits for classical sequential growth models. Random Struct. Alg. 36 218250.CrossRefGoogle Scholar
[8]Brightwell, G. and Luczak, M. (2011) Order-invariant measures on causal sets. Ann. Appl. Probab. 21 14931536.CrossRefGoogle Scholar
[9]Frame, J. S., Robinson, G. de B. and Thrall, R. M. (1954) The hook graphs of the symmetric group. Canad. J. Math. 6 316324.CrossRefGoogle Scholar
[10]Georgii, H.-O. (1988) Gibbs Measures and Phase Transitions, Vol. 9 of De Gruyter Studies in Mathematics, de Gruyter.CrossRefGoogle Scholar
[11]Gnedin, A. and Kerov, S. (2000) The Plancherel measure of the Young–Fibonacci graph. Math. Proc. Cambridge Philos. Soc. 129 433446.CrossRefGoogle Scholar
[12]Graham, R. L., Yao, A. C. and Yao, F. F. (1980) Some monotonicity properties of partial orders. SIAM J. Alg. Discrete Methods 1 251258.CrossRefGoogle Scholar
[13]Grimmett, G. R. and Stirzaker, D. (2001) Probability and Random Processes, Oxford University Press.CrossRefGoogle Scholar
[14]Kerov, S. (1996) The boundary of Young lattice and random Young tableaux. In Formal Power Series and Algebraic Combinatorics: New Brunswick 1994, Vol. 24 of DIMACS Ser. Discrete Math. Theoret. Comput. Sci., AMS, pp. 33158.Google Scholar
[15]Rideout, D. P. and Sorkin, R. D. (2000) Classical sequential growth dynamics for causal sets. Phys. Rev. D (3) 61 024002.CrossRefGoogle Scholar
[16]Rideout, D. P. and Sorkin, R. D. (2001) Evidence for a continuum limit in causal set dynamics. Phys. Rev. D (3) 63 104011.CrossRefGoogle Scholar
[17]Ross, S. M. (2007) Introduction to Probability Models, ninth edition, Academic Press.Google Scholar
[18]Vershik, A. M. and Kerov, S. K. (1977) Asymptotics of the Plancherel measure of the symmetric group and the limiting shape of Young tableaux. Soviet Math. Dokl. 18 527531.Google Scholar
[19]Vershik, A. M. and Tsilevich, N. V. (2006) Markov measures on Young tableaux and induced representations of the infinite symmetric group (in Russian). Teor. Veroyatn. Primen. 51 4763. Translation in Theory Probab. Appl. 51 (2007), 211–223.Google Scholar
[20]Williams, D. (2007) Probability with Martingales, Cambridge University Press.Google Scholar
[21]Winkler, P. (1986) Correlation and order. Contemporary Mathematics 57 151174.CrossRefGoogle Scholar