We consider catalytic branching populations. They consist of a catalyst population evolving according to a critical binary branching process in continuous time with a constant branching rate and a reactant population with a branching rate proportional to the number of catalyst individuals alive. The reactant forms a process in random medium.
We describe asymptotically the genealogy of catalytic branching populations coded as the induced forest of ℝ-trees using the many individuals—rapid branching continuum limit. The limiting continuum genealogical forests are then studied in detail from both the quenched and annealed points of view. The result is obtained by constructing a contour process and analyzing the appropriately rescaled version and its limit. The genealogy of the limiting forest is described by a point process. We compare geometric properties and statistics of the reactant limit forest with those of the “classical” forest.
References
[1] Aldous, D. (1991). The continuum random tree. I. Ann. Probab. 19 1–28.
[2] Aldous, D. (1991). The continuum random tree. II. An overview. In Stochastic Analysis (Durham, 1990). London Mathematical Society Lecture Note Series 167 23–70. Cambridge Univ. Press, Cambridge.
[3] Aldous, D. (1993). The continuum random tree. III. Ann. Probab. 21 248–289.
[4] Aldous, D. J. (1999). Deterministic and stochastic models for coalescence (aggregation and coagulation): A review of the mean-field theory for probabilists. Bernoulli 5 3–48.
[5] Athreya, S. and Winter, A. (2005). Spatial coupling of neutral measure-valued population models. Stochastic Process. Appl. 115 891–906.
[6] Chiswell, I. (2001). Introduction to Λ-Trees. World Scientific, River Edge, NJ.
[7] Donnelly, P. and Kurtz, T. G. (1999). Particle representations for measure-valued population models. Ann. Probab. 27 166–205.
[8] Dress, A. W. M. (1984). Trees, tight extensions of metric spaces, and the cohomological dimension of certain groups: A note on combinatorial properties of metric spaces. Adv. in Math. 53 321–402.
Mathematical Reviews (MathSciNet):
MR753872
[9] Dress, A. W. M., Moulton, V. and Terhalle, W. F. (1996). T-theorie. Europ. J. Combinatorics 17 161–175.
[10] Dress, A. W. M. and Terhalle, W. F. (1996). The real tree. Adv. in Math. 120 283–301.
[11] Duquesne, T. and Le Gall, J.-F. (2002). Random trees, Lévy processes and spatial branching processes. Astérisque 281 vi–147.
[12] Ethier, S. N. and Kurtz, T. G. (1986). Markov Processes: Characterization and Convergence. Wiley, New York.
Mathematical Reviews (MathSciNet):
MR838085
[13] Evans, S. N., Pitman, J. and Winter, A. (2006). Rayleigh processes, real trees, and root growth with re-grafting. Probab. Theory Related Fields 134 81–126.
[14] Evans, S. N. and Winter, A. (2006). Subtree prune and re-graft: A reversible real-tree valued Markov chain. Ann. Probab. To appear. 34 918–961.
[15] Feller, W. (1968). An Introduction to Probability Theory and Its Applications. Vol. I, 3rd ed. Wiley, New York.
Mathematical Reviews (MathSciNet):
MR228020
[16] Greven, A., Klenke, A. and Wakolbinger, A. (1999). The longtime behavior of branching random walk in a catalytic medium. Electron. J. Probab. 4 80.
[17] Kurtz, T. G. (1992). Averaging for martingale problems and stochastic approximation. In Applied Stochastic Analysis (New Brunswick, NJ, 1991). Lecture Notes in Control and Information Sciences 177 186–209. Springer, Berlin.
[18] Lamperti, J. (1967). The limit of a sequence of branching processes. Z. Wahrsch. Verw. Gebiete 7 271–288.
Mathematical Reviews (MathSciNet):
MR217893
[19] Le Gall, J.-F. (1999). Spatial Branching Processes, Random Snakes and Partial Differential Equations. Birkhäuser, Basel.
[20] Penssel, C. (2003). Interacting Feller diffusions in catalytic media. Ph.D. thesis, Institute of Math., Erlangen, Germany.
[21] Pitman, J. (2006). Combinatorial Stochastic Processes. Lecture Notes in Mathematics 1875. Springer, Berlin.
[22] Popovic, L. (2004). Asymptotic genealogy of a critical branching process. Ann. Appl. Probab. 14 2120–2148.
[23] Protter, P. E. (1977). On the existence, uniqueness, convergence and explosions of solutions of systems of stochastic integral equations. Ann. Probab. 5 243–261.
Mathematical Reviews (MathSciNet):
MR431380
[24] Rogers, L. C. G. and Williams, D. (1987). Diffusions, Markov Processes, and Martingales: Itô Calculus. Wiley Series in Probability and Mathematical Statistics: Probability and Mathematical Statistics. 2. Wiley, New York.
Mathematical Reviews (MathSciNet):
MR921238
[25] Revuz, D. and Yor, M. (1999). Continuous Martingales and Brownian Motion, 3rd ed. Grundlehren der Mathematischen Wissenschaften [Fundamental Principles of Mathematical Sciences] 293. Springer, Berlin.
[26] Stroock, D. W. and Varadhan, S. R. S. (1969). Diffusion processes with continuous coefficients. I. Comm. Pure Appl. Math. 22 345–400.
Mathematical Reviews (MathSciNet):
MR253426
[27] Terhalle, W. F. (1997). R-trees and symmetric differences of sets. European J. Combin. 18 825–833.