RT Journal Article T1 A double-zero bifurcation in a Lorenz-like system A1 Algaba Durán, Antonio A1 Domínguez Moreno, María Cinta A1 Merino Morlesín, Manuel A1 Rodríguez Luis, Alejandro José AB The Lorenz system presents a double-zero bifurcation (a double-zero eigenvalue with geometric multiplicity two). However, its study by means of standard techniques is not possible because it occurs for a non-isolated equilibrium. To circumvent this difficulty, we add in the third equation a new term, . In this Lorenz-like system, the analysis of the double-zero bifurcation of the equilibrium at the origin guarantees, for certain values of the parameters, the existence of a heteroclinic cycle between the two equilibria located on the z-axis. The numerical continuation in parameter space of the locus of heteroclinic connections allows to detect various degeneracies of codimension two and three, some of which have not been previously studied in the literature. These bifurcations are organizing centers of the complicated dynamics exhibited by this system. Furthermore, studying how the bifurcation sets evolve when D tends to zero, we are able to explain, in the Lorenz system, the origin of several global connections which are related to T-point heteroclinic loops. PB Springer SN 0924-090X SN 1573-269X (electrónico) YR 2023 FD 2023-12 LK https://hdl.handle.net/10272/23278 UL https://hdl.handle.net/10272/23278 LA eng NO Algaba, A., Domínguez-Moreno, M. C., Merino, M., & Rodríguez-Luis, A. J. (2023). A double-zero bifurcation in a Lorenz-like system. In Nonlinear Dynamics (Vol. 112, Issue 3, pp. 2305–2330). Springer Science and Business Media LLC. https://doi.org/10.1007/s11071-023-09130-1 NO Funding for open access publishing: Universidad de Sevilla/CBUA This work has been partially supported by the Ministerio de Economía y Competitividad (MTM2017-87915-C2-1-P), by the Ministerio de Ciencia, Innovación y Universidades (PGC2018-096265-B-I00, PID2021-123200NB-I00) and by the Consejería de Economía, Innovación, Ciencia y Empleo de la Junta de Andalucía (projects FQM-276, TIC-0130, P20_01160 and UHU-1260150). DS Repositorio Institucional de la Universidad de Huelva RD 31 may 2026