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Asymptotic behaviour of ancestral lineages in subcritical continuous-state branching populations. (English) Zbl 1491.60149

Summary: Consider the population model with infinite size associated to subcritical continuous-state branching processes (CSBP). We study the flow of ancestral lineages as time goes to the past and show that, properly renormalized, it converges almost surely to the inverse of a drift-free subordinator whose Laplace exponent is explicit in terms of the branching mechanism. The inverse subordinator is shown to be partitioning the current population into ancestral families with distinct common ancestors. When Grey’s condition is satisfied, the population comes from a discrete set of ancestors and the ancestral families have i.i.d. sizes distributed according to the quasi-stationary distribution of the CSBP conditioned on non-extinction. When Grey’s condition is not satisfied, the population comes from a continuum of ancestors which is described as the set of increase points \(\mathcal{S}\) of the limiting inverse subordinator. The proof is based on a general result for stochastically monotone processes of independent interest, which relates \(\theta \)-invariant measures and \(\theta \)-invariant functions for a process and its Siegmund dual.

MSC:

60J80 Branching processes (Galton-Watson, birth-and-death, etc.)
60J70 Applications of Brownian motions and diffusion theory (population genetics, absorption problems, etc.)
92D25 Population dynamics (general)
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[1] Asmussen, Soren; Sigman, Karl, Monotone stochastic recursions and their duals, Probab. Engrg. Inform. Sci., 10, 1, 1-20 (1996) · Zbl 1095.60519
[2] Barbour, Andrew D., The asymptotic behaviour of birth and death and some related processes, Adv. Appl. Probab., 7, 28-43 (1975) · Zbl 0306.60054
[3] Bertoin, Jean, Subordinators: Examples and Applications, 1-91 (1999), Springer Berlin Heidelberg: Springer Berlin Heidelberg Berlin, Heidelberg · Zbl 0955.60046
[4] Bertoin, Jean; Fontbona, Joaquin; Martínez, Servet, On prolific individuals in a supercritical continuous-state branching process, J. Appl. Probab., 45, 3, 714-726 (2008) · Zbl 1154.60066
[5] Bertoin, Jean; Le Gall, Jean-François, The Bolthausen-Sznitman coalescent and the genealogy of continuous-state branching processes, Probab. Theory Related Fields, 117, 2, 249-266 (2000) · Zbl 0963.60086
[6] Bingham, Nick, Continuous branching processes and spectral positivity, Stochastic Process. Appl., 4, 3, 217-242 (1976) · Zbl 0338.60051
[7] Bingham, Nick; Goldie, Charles; Teugels, Jozef, Regular Variation, Encyclopedia of Mathematics and its Applications (1987), Cambridge University Press: Cambridge University Press Cambridge, Cambridgeshire, New York, Includes indexes · Zbl 0617.26001
[8] Chung, Kai Lai, A Course in Probability Theory (1968), Harcourt, Brace & World, Inc.: Harcourt, Brace & World, Inc. New York · Zbl 0980.60001
[9] Clifford, Peter; Sudbury, Aidan, A sample path proof of the duality for stochastically monotone Markov processes, Ann. Probab., 13, 2, 558-565 (1985) · Zbl 0563.60062
[10] Curtiss, John H., A note on the theory of moment generating functions, Ann. Math. Statist., 13, 430-433 (1942) · Zbl 0063.01024
[11] Duquesne, Thomas; Labbé, Cyril, On the Eve property for CSBP, Electron. J. Probab., 19, 6, 31 (2014) · Zbl 1287.60100
[12] Feller, William, An Introduction to Probability Theory and Its Applications. Vol. II (1971), John Wiley & Sons, Inc.: John Wiley & Sons, Inc. New York-London-Sydney · Zbl 0219.60003
[13] Foucart, Clément; Ma, Chunhua, Continuous-state branching processes, extremal processes and super-individuals, Ann. Inst. H. Poincaré Probab. Statist., 55, 2, 1061-1086 (2019) · Zbl 1466.60176
[14] Foucart, Clément; Ma, Chunhua; Mallein, Bastien, Coalescences in continuous-state branching processes, Electron. J. Probab., 24, 103 (2019) · Zbl 1427.60177
[15] Foucart, Clément; Ma, Chunhua; Yuan, Linglong, Limit theorems for continuous-state branching processes with immigration (2021), ArXiv eprint 2009.12564, to appear in Advances in Applied Probability 54.2 (June 2022) · Zbl 1492.60237
[16] Grey, David, Asymptotic behaviour of continuous time, continuous state-space branching processes, J. Appl. Probab., 11, 669-677 (1974) · Zbl 0301.60060
[17] Jiřina, Miloslav, Stochastic branching processes with continuous state space, Czechoslovak Math. J., 8, 83, 292-313 (1958) · Zbl 0168.38602
[18] Johnston, Samuel G. G.; Lambert, Amaury, The coalescent structure of uniform and Poisson samples from multitype branching processes (2021), ArXiv eprint 1912.00198
[19] Labbé, Cyril, Genealogy of flows of continuous-state branching processes via flows of partitions and the eve property, Ann. Inst. H. Poincaré Probab. Statist., 50, 3, 732-769 (2014) · Zbl 1308.60099
[20] Lagerås, Andreas Nordvall, A renewal-process-type expression for the moments of inverse subordinators, J. Appl. Probab., 42, 4, 1134-1144 (2005) · Zbl 1094.60057
[21] Lambert, Amaury, Coalescence times for the branching process, Adv. Appl. Probab., 35, 4, 1071-1089 (2003) · Zbl 1040.60073
[22] Lambert, Amaury, Quasi-stationary distributions and the continuous-state branching process conditioned to be never extinct, Electron. J. Probab., 12, 14, 420-446 (2007) · Zbl 1127.60082
[23] Lambert, Amaury; Popovic, Lea, The coalescent point process of branching trees, Ann. Appl. Probab., 23, 1, 99-144 (2013) · Zbl 1268.60107
[24] Lamperti, John, Continuous state branching processes, Bull. Amer. Math. Soc., 73, 382-386 (1967) · Zbl 0173.20103
[25] Li, Zeng-Hu, Asymptotic behaviour of continuous time and state branching processes, J. Aust. Math. Soc. Ser. A, 68, 1, 68-84 (2000) · Zbl 0960.60072
[26] Li, Zenghu, (Measure-Valued Branching Markov Processes. Measure-Valued Branching Markov Processes, Probability and its Applications (New York) (2011), Springer: Springer Heidelberg) · Zbl 1235.60003
[27] Li, Yangrong; Pakes, Anthony G.; Li, Jia; Gu, Anhui, The limit behavior of dual Markov branching processes, J. Appl. Probab., 45, 1, 176-189 (2008) · Zbl 1137.60039
[28] Pakes, Anthony G., Convergence rates and limit theorems for the dual Markov branching process, J. Probab. Stat., 13 (2017) · Zbl 1431.60101
[29] Siegmund, David, The equivalence of absorbing and reflecting barrier problems for stochastically monotone Markov processes, Ann. Probab., 4, 6, 914-924 (1976) · Zbl 0364.60109
[30] Silverstein, Martin, A new approach to local times, J. Math. Mech., 17, 1023-1054 (1967) · Zbl 0184.41101
[31] Theodore Cox, John; Rösler, Uwe, A duality relation for entrance and exit laws for Markov processes, Stochastic Process. Appl., 16, 2, 141-156 (1984) · Zbl 0523.60068
[32] Veillette, Mark; Taqqu, Murad S., Using differential equations to obtain joint moments of first-passage times of increasing Lévy processes, Statist. Probab. Lett., 80, 7, 697-705 (2010) · Zbl 1203.60049
[33] Widder, David, (Laplace Transform. Laplace Transform, Mathematics Series (1941), Princeton Univ. Press) · Zbl 0063.08245
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