title: Data collapse, scaling functions, and analytical solutions of generalized growth models.
abstract: We consider a nontrivial one-species population dynamics model with finite and infinite carrying capacities. Time-dependent intrinsic and extrinsic growth rates are considered in these models. Through the model per capita growth rate we obtain a heuristic general procedure to generate scaling functions to collapse data into a simple linear behavior even if an extrinsic growth rate is included. With this data collapse, all the models studied become independent from the parameters and initial condition. Analytical solutions are found when time-dependent coefficients are considered. These solutions allow us to perceive nontrivial transitions between species extinction and survival and to calculate the transition's critical exponents. Considering an extrinsic growth rate as a cancer treatment, we show that the relevant quantity depends not only on the intensity of the treatment, but also on when the cancerous cell growth is maximum.
authors.affiliation: Departamento de Física, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brazil. brenno@usp.br
authors.forename: Brenno Caetano Troca
authors.initials: BC
authors.lastname: Cabella
authors.forename: Alexandre Souto
authors.initials: AS
authors.lastname: Martinez
authors.forename: Fabiano
authors.initials: F
authors.lastname: Ribeiro
mesh_terms: D053476:Extinction, Biological; D008962:Models, Theoretical; D011157:Population Dynamics; D016019:Survival Analysis; D013997:Time Factors