Deeptajyoti Sen

@srmap.edu.in

Assistant Professor, Department of Mathematics and Statistics
SRM University AP

EDUCATION

M.Sc. in Mathematics, Ph.D. in Applied Mathematics

RESEARCH, TEACHING, or OTHER INTERESTS

Modeling and Simulation, Ecological Modeling, Modeling and Simulation
13

Scopus Publications

411

Scholar Citations

7

Scholar h-index

6

Scholar i10-index

Scopus Publications

  • Seasonal synchronization and unpredictability in epidemic models with waning immunity and healthcare thresholds
    Veronika Eclerová, Deeptajyoti Sen, Lenka Přibylová
    Scientific Reports, 2025
    This paper explores a model integrating healthcare capacity thresholds and seasonal effects to investigate the synchronization of epidemic cycles with seasonal transmission rates, using parameters reflective of the COVID-19 pandemic. Through bifurcation analysis in the epi-seasonal domain, we identify regions of significant seasonal synchronization related to transmission rate fluctuations, waning immunity, and healthcare capacity thresholds. The model highlights four sources of unpredictability: chaotic regimes, quasiperiodicity, proximity to SNIC or transcritical bifurcations, and bistability. Our findings reveal that chaotic regimes are more predictable than quasiperiodic regimes in epidemiological terms. Synchronizing outbreaks with seasonal cycles, even in chaotic regimes, predominantly results in significant winter outbreaks. Conversely, quasiperiodicity allows outbreaks to occur at any time of the year. Near eradication unpredictability aligns with historical pertussis data, underscoring the model’s relevance to real-world epidemics and vaccine schedules. Additionally, we identify a bistability region with potential for abrupt shifts in disease prevalence, triggered by superspreading events or migration.
  • Exploring population oscillations: Cross-coupling and dispersal effects in prey–predator dynamics
    Debjani Mondal, Moitri Sen, Deeptajyoti Sen
    Physica D Nonlinear Phenomena, 2025
  • Complex dynamics in prey-predator systems with cross-coupling: Exploring nonlinear interactions and population oscillations
    Deeptajyoti Sen, Lenka Přibylová
    Communications in Nonlinear Science and Numerical Simulation, 2024
  • Does mutual interference stabilize prey–predator model with Bazykin–Crowley–Martin trophic function?
    Yuri Tyutyunov, Deeptajyoti Sen, Malay Banerjee
    Mathematical Biosciences, 2024
  • Destabilization of a seasonal synchronization in a population model with a seasonally varying Allee effect
    Lenka Přibylová, Deeptajyoti Sen, Veronika Eclerová
    Applied Mathematics and Computation, 2024
  • Influence of the Allee effect on extreme events in coupled three-species systems
    Deeptajyoti Sen, Sudeshna Sinha
    Journal of Biosciences, 2022
  • Bifurcation analysis of the predator–prey model with the Allee effect in the predator
    Deeptajyoti Sen, Saktipada Ghorai, Malay Banerjee, Andrew Morozov
    Journal of Mathematical Biology, 2022
    The use of predator–prey models in theoretical ecology has a long history, and the model equations have largely evolved since the original Lotka–Volterra system towards more realistic descriptions of the processes of predation, reproduction and mortality. One important aspect is the recognition of the fact that the growth of a population can be subject to an Allee effect, where the per capita growth rate increases with the population density. Including an Allee effect has been shown to fundamentally change predator–prey dynamics and strongly impact species persistence, but previous studies mostly focused on scenarios of an Allee effect in the prey population. Here we explore a predator–prey model with an ecologically important case of the Allee effect in the predator population where it occurs in the numerical response of predator without affecting its functional response. Biologically, this can result from various scenarios such as a lack of mating partners, sperm limitation and cooperative breeding mechanisms, among others. Unlike previous studies, we consider here a generic mathematical formulation of the Allee effect without specifying a concrete parameterisation of the functional form, and analyse the possible local bifurcations in the system. Further, we explore the global bifurcation structure of the model and its possible dynamical regimes for three different concrete parameterisations of the Allee effect. The model possesses a complex bifurcation structure: there can be multiple coexistence states including two stable limit cycles. Inclusion of the Allee effect in the predator generally has a destabilising effect on the coexistence equilibrium. We also show that regardless of the parametrisation of the Allee effect, enrichment of the environment will eventually result in extinction of the predator population.
  • Enhancement of extreme events through the Allee effect and its mitigation through noise in a three species system
    Deeptajyoti Sen, Sudeshna Sinha
    Scientific Reports, 2021
    We consider the dynamics of a three-species system incorporating the Allee Effect, focussing on its influence on the emergence of extreme events in the system. First we find that under Allee effect the regular periodic dynamics changes to chaotic. Further, we find that the system exhibits unbounded growth in the vegetation population after a critical value of the Allee parameter. The most significant finding is the observation of a critical Allee parameter beyond which the probability of obtaining extreme events becomes non-zero for all three population densities. Though the emergence of extreme events in the predator population is not affected much by the Allee effect, the prey population shows a sharp increase in the probability of obtaining extreme events after a threshold value of the Allee parameter, and the vegetation population also yields extreme events for sufficiently strong Allee effect. Lastly we consider the influence of additive noise on extreme events. First, we find that noise tames the unbounded vegetation growth induced by Allee effect. More interestingly, we demonstrate that stochasticity drastically diminishes the probability of extreme events in all three populations. In fact for sufficiently high noise, we do not observe any more extreme events in the system. This suggests that noise can mitigate extreme events, and has potentially important bearing on the observability of extreme events in naturally occurring systems.
  • Allee effect in prey's growth reduces the dynamical complexity in prey-predator model with generalist predator
    Deeptajyoti Sen, S. Ghorai, Swarnali Sharma, Malay Banerjee
    Applied Mathematical Modelling, 2021
  • Rich Bifurcation Structure of Prey-Predator Model Induced by the Allee Effect in the Growth of Generalist Predator
    Deeptajyoti Sen, Sergei Petrovskii, S. Ghorai, Malay Banerjee
    International Journal of Bifurcation and Chaos, 2020
    Prey–predator models are building blocks for many food-chain and food-web models in theoretical population biology. These models can be divided into two groups depending on the nature of predators, namely, specialist predator and generalist predator. Generalist predators can survive in the absence of prey but specialist predators go to extinction. Prey–predator models with specialist predator and Allee effect in prey growth have been investigated by several researchers and various types of interesting dynamics have been reported. In this paper, we consider a prey–predator model with generalist predator subject to Allee effect in predator’s growth rate. In general, a prey–predator system with saturating functional response can be destabilized due to the increase of the carrying capacity of prey which is known as paradox of enrichment. In our model with Allee effect in predator growth, we have shown that increase in carrying capacity of prey helps the populations to survive in a coexistence steady state. The considered model is capable of producing bistable dynamics for a reasonable range of parameter values. The complete dynamics of the system are quite rich and all possible local and global bifurcations are studied to understand the dynamics of the model. Analytical results are verified with numerical examples and successive bifurcations are identified with the help of bifurcation diagrams.
  • Predator overcomes the Allee effect due to indirect prey–taxis
    Yuri V. Tyutyunov, Deeptajyoti Sen, Lyudmila I. Titova, Malay Banerjee
    Ecological Complexity, 2019
  • Allee effect in prey versus hunting cooperation on predator-enhancement of stable coexistence
    Deeptajyoti Sen, S. Ghorai, Malay Banerjee
    International Journal of Bifurcation and Chaos, 2019
  • Complex dynamics of a three species prey-predator model with intraguild predation
    Deeptajyoti Sen, S. Ghorai, Malay Banerjee
    Ecological Complexity, 2018

RECENT SCHOLAR PUBLICATIONS

  • Seasonal synchronization and unpredictability in epidemic models with waning immunity and healthcare thresholds
    V Eclerová, D Sen, L Přibylová
    Scientific Reports 15 (1), 17190 , 2025
    2025.0
    Citations: 5
  • Exploring population oscillations: Cross-coupling and dispersal effects in prey–predator dynamics
    D Mondal, M Sen, D Sen
    Physica D: Nonlinear Phenomena 472, 134525 , 2025
    2025.0
    Citations: 4
  • Complex dynamics in prey-predator systems with cross-coupling: Exploring nonlinear interactions and population oscillations
    D Sen, L Přibylová
    Communications in Nonlinear Science and Numerical Simulation 137, 108154 , 2024
    2024.0
    Citations: 7
  • Does mutual interference stabilize prey–predator model with Bazykin–Crowley–Martin trophic function?
    Y Tyutyunov, D Sen, M Banerjee
    Mathematical Biosciences 372, 109201 , 2024
    2024.0
    Citations: 6
  • Destabilization of a seasonal synchronization in a population model with a seasonally varying Allee effect
    L Přibylová, D Sen, V Eclerová
    Applied Mathematics and Computation 462, 128331 , 2024
    2024.0
    Citations: 8
  • A Novel Approach to Analyzing Seasonal Patterns in Epidemics Using a Higher-Dimensional State Space
    L Přibylová, V Eclerová, D Sen
    2023.0
  • Lenka Přibylová, Deeptajyoti Sen, Veronika Eclerová
    L Přibylová, D Sen, V Eclerová
    2023.0
  • Influence of the Allee effect on extreme events in coupled three-species systems: D Sen and S Sinha
    D Sen, S Sinha
    Journal of Biosciences 47 (2), 30 , 2022
    2022.0
    Citations: 7
  • Bifurcation analysis of the predator–prey model with the Allee effect in the predator
    D Sen, S Ghorai, M Banerjee, A Morozov
    Journal of mathematical biology 84 (1), 7 , 2022
    2022.0
    Citations: 90
  • Enhancement of extreme events through the Allee effect and its mitigation through noise in a three species system
    D Sen, S Sinha
    Scientific Reports 11 (1), 20913 , 2021
    2021.0
    Citations: 5
  • Allee effect in prey’s growth reduces the dynamical complexity in prey-predator model with generalist predator
    D Sen, S Ghorai, S Sharma, M Banerjee
    Applied Mathematical Modelling 91, 768-790 , 2021
    2021.0
    Citations: 69
  • Rich bifurcation structure of prey-predator model induced by the Allee effect in the growth of generalist predator
    D Sen, S Petrovskii, S Ghorai, M Banerjee
    International Journal of Bifurcation and Chaos 30 (6), 2050084 , 2020
    2020.0
    Citations: 38
  • Predator overcomes the Allee effect due to indirect prey–taxis
    YV Tyutyunov, D Sen, LI Titova, M Banerjee
    Ecological complexity 39, 100772 , 2019
    2019.0
    Citations: 35
  • Allee effect in prey versus hunting cooperation on predator—enhancement of stable coexistence
    D Sen, S Ghorai, M Banerjee
    International Journal of Bifurcation and Chaos 29 (06), 1950081 , 2019
    2019.0
    Citations: 71
  • Complex dynamics of a three species prey-predator model with intraguild predation
    D Sen, S Ghorai, M Banerjee
    Ecological complexity 34, 9-22 , 2018
    2018.0
    Citations: 66
  • DYNAMICAL BEHAVIOR OF PREDATOR-PREY MODEL SUBJECTED TO ALLEE EFFECT IN THE PREDATOR
    D Sen

MOST CITED SCHOLAR PUBLICATIONS

  • Bifurcation analysis of the predator–prey model with the Allee effect in the predator
    D Sen, S Ghorai, M Banerjee, A Morozov
    Journal of mathematical biology 84 (1), 7 , 2022
    2022.0
    Citations: 90
  • Allee effect in prey versus hunting cooperation on predator—enhancement of stable coexistence
    D Sen, S Ghorai, M Banerjee
    International Journal of Bifurcation and Chaos 29 (06), 1950081 , 2019
    2019.0
    Citations: 71
  • Allee effect in prey’s growth reduces the dynamical complexity in prey-predator model with generalist predator
    D Sen, S Ghorai, S Sharma, M Banerjee
    Applied Mathematical Modelling 91, 768-790 , 2021
    2021.0
    Citations: 69
  • Complex dynamics of a three species prey-predator model with intraguild predation
    D Sen, S Ghorai, M Banerjee
    Ecological complexity 34, 9-22 , 2018
    2018.0
    Citations: 66
  • Rich bifurcation structure of prey-predator model induced by the Allee effect in the growth of generalist predator
    D Sen, S Petrovskii, S Ghorai, M Banerjee
    International Journal of Bifurcation and Chaos 30 (6), 2050084 , 2020
    2020.0
    Citations: 38
  • Predator overcomes the Allee effect due to indirect prey–taxis
    YV Tyutyunov, D Sen, LI Titova, M Banerjee
    Ecological complexity 39, 100772 , 2019
    2019.0
    Citations: 35
  • Destabilization of a seasonal synchronization in a population model with a seasonally varying Allee effect
    L Přibylová, D Sen, V Eclerová
    Applied Mathematics and Computation 462, 128331 , 2024
    2024.0
    Citations: 8
  • Complex dynamics in prey-predator systems with cross-coupling: Exploring nonlinear interactions and population oscillations
    D Sen, L Přibylová
    Communications in Nonlinear Science and Numerical Simulation 137, 108154 , 2024
    2024.0
    Citations: 7
  • Influence of the Allee effect on extreme events in coupled three-species systems: D Sen and S Sinha
    D Sen, S Sinha
    Journal of Biosciences 47 (2), 30 , 2022
    2022.0
    Citations: 7
  • Does mutual interference stabilize prey–predator model with Bazykin–Crowley–Martin trophic function?
    Y Tyutyunov, D Sen, M Banerjee
    Mathematical Biosciences 372, 109201 , 2024
    2024.0
    Citations: 6
  • Seasonal synchronization and unpredictability in epidemic models with waning immunity and healthcare thresholds
    V Eclerová, D Sen, L Přibylová
    Scientific Reports 15 (1), 17190 , 2025
    2025.0
    Citations: 5
  • Enhancement of extreme events through the Allee effect and its mitigation through noise in a three species system
    D Sen, S Sinha
    Scientific Reports 11 (1), 20913 , 2021
    2021.0
    Citations: 5
  • Exploring population oscillations: Cross-coupling and dispersal effects in prey–predator dynamics
    D Mondal, M Sen, D Sen
    Physica D: Nonlinear Phenomena 472, 134525 , 2025
    2025.0
    Citations: 4
  • A Novel Approach to Analyzing Seasonal Patterns in Epidemics Using a Higher-Dimensional State Space
    L Přibylová, V Eclerová, D Sen
    2023.0
  • Lenka Přibylová, Deeptajyoti Sen, Veronika Eclerová
    L Přibylová, D Sen, V Eclerová
    2023.0
  • DYNAMICAL BEHAVIOR OF PREDATOR-PREY MODEL SUBJECTED TO ALLEE EFFECT IN THE PREDATOR
    D Sen