Modeling Marital Stability: A Dynamical Systems Analysis of Extramarital Affairs and Divorce
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Abstract
This study develops and analyzes a nonlinear mathematical model to describe the dynamics of marriage, extramarital affairs, marital breakdown, and divorce. The population is divided into five compartments: single $S(t)$, married $M(t)$, individuals in extramarital affairs $A(t)$, broken marriages $B(t)$, and divorced $D(t)$. The model is formulated as a system of nonlinear ordinary differential equations capturing transitions between these states through parameters representing marriage formation, affair initiation, reconciliation, separation, and divorce. Basic qualitative properties, including positivity and boundedness of solutions, are established to ensure the model is well posed. Equilibrium analysis reveals the trivial equilibrium $E_T=(0,0,0,0,0)$, the divorce-free equilibrium $E_0=(S^0,M^0,0,0,0)$, and a positive endemic equilibrium $E^*=(S^*,M^*,A^*,B^*,D^*)$. Stability is investigated via the Jacobian matrix and characteristic equation. The basic reproduction number $R_0$, derived using the next-generation matrix method, determines whether marital instability spreads in the population. The divorce-free equilibrium is locally asymptotically stable when $R_0<1$, whereas persistent instability occurs when $R_0>1$. Sensitivity analysis and numerical simulations are performed to examine the influence of key parameters, including marriage formation rate $\alpha$, affair initiation rate $\gamma$, instability rate $\sigma$, and reconciliation rate $\xi$. Phase portraits, parameter variation diagrams, and reproduction number plots confirm the analytical results. The findings highlight the roles of extramarital affairs and reconciliation in shaping marital stability and provide a quantitative framework for understanding long-term marriage and divorce dynamics.
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References
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Cite This Article
TY - JOUR AU - Pippal, Sarita AU - Ranga, Ajay PY - 2026 DA - 2026/07/24 TI - Modeling Marital Stability: A Dynamical Systems Analysis of Extramarital Affairs and Divorce JO - Journal of Mathematics and Interdisciplinary Applications T2 - Journal of Mathematics and Interdisciplinary Applications JF - Journal of Mathematics and Interdisciplinary Applications VL - 2 IS - 3 SP - 164 EP - 191 DO - 10.62762/JMIA.2026.666866 UR - https://www.icck.org/article/abs/JMIA.2026.666866 KW - dynamical systems KW - marital stability KW - extramarital affairs KW - divorce dynamics KW - equilibrium analysis KW - sensitivity analysis AB - This study develops and analyzes a nonlinear mathematical model to describe the dynamics of marriage, extramarital affairs, marital breakdown, and divorce. The population is divided into five compartments: single $S(t)$, married $M(t)$, individuals in extramarital affairs $A(t)$, broken marriages $B(t)$, and divorced $D(t)$. The model is formulated as a system of nonlinear ordinary differential equations capturing transitions between these states through parameters representing marriage formation, affair initiation, reconciliation, separation, and divorce. Basic qualitative properties, including positivity and boundedness of solutions, are established to ensure the model is well posed. Equilibrium analysis reveals the trivial equilibrium $E_T=(0,0,0,0,0)$, the divorce-free equilibrium $E_0=(S^0,M^0,0,0,0)$, and a positive endemic equilibrium $E^*=(S^*,M^*,A^*,B^*,D^*)$. Stability is investigated via the Jacobian matrix and characteristic equation. The basic reproduction number $R_0$, derived using the next-generation matrix method, determines whether marital instability spreads in the population. The divorce-free equilibrium is locally asymptotically stable when $R_01$. Sensitivity analysis and numerical simulations are performed to examine the influence of key parameters, including marriage formation rate $\alpha$, affair initiation rate $\gamma$, instability rate $\sigma$, and reconciliation rate $\xi$. Phase portraits, parameter variation diagrams, and reproduction number plots confirm the analytical results. The findings highlight the roles of extramarital affairs and reconciliation in shaping marital stability and provide a quantitative framework for understanding long-term marriage and divorce dynamics. SN - 3070-393X PB - Institute of Central Computation and Knowledge LA - English ER -
@article{Pippal2026Modeling,
author = {Sarita Pippal and Ajay Ranga},
title = {Modeling Marital Stability: A Dynamical Systems Analysis of Extramarital Affairs and Divorce},
journal = {Journal of Mathematics and Interdisciplinary Applications},
year = {2026},
volume = {2},
number = {3},
pages = {164-191},
doi = {10.62762/JMIA.2026.666866},
url = {https://www.icck.org/article/abs/JMIA.2026.666866},
abstract = {This study develops and analyzes a nonlinear mathematical model to describe the dynamics of marriage, extramarital affairs, marital breakdown, and divorce. The population is divided into five compartments: single \$S(t)\$, married \$M(t)\$, individuals in extramarital affairs \$A(t)\$, broken marriages \$B(t)\$, and divorced \$D(t)\$. The model is formulated as a system of nonlinear ordinary differential equations capturing transitions between these states through parameters representing marriage formation, affair initiation, reconciliation, separation, and divorce. Basic qualitative properties, including positivity and boundedness of solutions, are established to ensure the model is well posed. Equilibrium analysis reveals the trivial equilibrium \$E\_T=(0,0,0,0,0)\$, the divorce-free equilibrium \$E\_0=(S^0,M^0,0,0,0)\$, and a positive endemic equilibrium \$E^*=(S^*,M^*,A^*,B^*,D^*)\$. Stability is investigated via the Jacobian matrix and characteristic equation. The basic reproduction number \$R\_0\$, derived using the next-generation matrix method, determines whether marital instability spreads in the population. The divorce-free equilibrium is locally asymptotically stable when \$R\_01\$. Sensitivity analysis and numerical simulations are performed to examine the influence of key parameters, including marriage formation rate \$\alpha\$, affair initiation rate \$\gamma\$, instability rate \$\sigma\$, and reconciliation rate \$\xi\$. Phase portraits, parameter variation diagrams, and reproduction number plots confirm the analytical results. The findings highlight the roles of extramarital affairs and reconciliation in shaping marital stability and provide a quantitative framework for understanding long-term marriage and divorce dynamics.},
keywords = {dynamical systems, marital stability, extramarital affairs, divorce dynamics, equilibrium analysis, sensitivity analysis},
issn = {3070-393X},
publisher = {Institute of Central Computation and Knowledge}
}
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Copyright © 2026 by the Author(s). Published by Institute of Central Computation and Knowledge. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made.
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