I am a physics Master’s student at the University of Montpellier, working across statistical physics, nonlinear dynamics and biophysical modeling through research at the Charles Coulomb Laboratory and independent projects. I also have a strong interest in the foundations of physics, particularly statistical mechanics and quantum mechanics.
Current research
1. Semiflexible magnetic polymers
Collaborators: Linda Delimi and Jean-Charles Walter
Laboratoire Charles Coulomb (L2C)
UMR 5221, CNRS–Université de Montpellier
Proteins can bridge distant parts of DNA, forming nucleoprotein complexes whose structure depends on both these interactions and DNA’s resistance to bending. In bacterial ParBS complexes, DNA’s persistence length is around 150 base pairs, while ParB’s binding footprint is only about 15-16 base pairs, making stiffness important at the protein-binding scale. Existing minimal models of ParBS complex formation have not systematically examined how stiffness and bridging jointly shape the phase behavior.
We address this through a semiflexible magnetic polymer model, where monomers carry interacting two-state spins and bends have an energetic cost. Combining Monte Carlo simulations on a three-dimensional face-centered-cubic lattice with variational free-energy bounds, we map the zero-field phase diagram of the model as a function of temperature and stiffness.
The model provides a minimal framework for understanding how bending rigidity and cooperative interactions organize polymers. Future work includes more efficient sampling of the very flexible limit and extending the phase diagram to nonzero magnetic fields, thus connecting the limiting regimes and developing the framework toward a fuller description of DNA-protein organization.
➤ Preprint: arXiv:2610.08958
Presented at:
➤ GDR ADN-Phys meeting, ENS de Lyon, Lyon, France (March-April, 2026).
➤ ANR project meeting, Bacterial DNA Segregation (BaDS), Laboratoire Charles Coulomb, Montpellier, France (April, 2026).
➤ Supercoiling @ Sète, scientific retreat, Sète, France (November, 2026). Upcoming.
This project grew out of my first-year Master’s internship at Laboratoire Charles Coulomb (L2C), funded by the IDIL Graduate Program, Université de Montpellier. I thank my supervisors Jean-Charles Walter and Linda Delimi for their guidance and encouragement throughout the research, and my professors and mentors Andrea Parmeggiani and Nils-Ole Walliser for their invaluable support throughout my first year.
2. Coupled oscillator networks with mixed-sign feedback
Independent research
Coupled oscillators can synchronize, keep moving or become pinned. In this project, I investigate these behaviors in fully connected active rotator networks with Kuramoto coupling, where all oscillators share the same positive intrinsic drive but local feedback varies in strength and sign. This isolates feedback heterogeneity without introducing differences in natural frequency.
Combining numerical simulations with analytical calculations, I show that stronger coupling can restore suppressed forward motion at weak feedback heterogeneity, and produce a coherently pinned group at sufficiently strong feedback disorder. In the weak-coupling, low-motion state, however, the oscillators gather around two opposing phases in an antipodal organization. At intermediate coupling, some oscillators drift backwards against the common drive - a behavior that cannot occur in a stationary mean field, and is driven by a time-dependent collective field.
The model demonstrates how mixed-sign feedback can reshape collective motion and phase organization, even when all the oscillators have the same intrinsic frequency. Future work includes studying the model on sparse networks and exploring different feedback distributions, alongside other extensions.
➤ Preprint: arXiv:2606.10032
➤ Code and data: GitHub repository
Presented at:
➤ 860th WE-Heraeus seminar: Half a Century of the Kuramoto Model: Explaining Emergent Order in Time and Space, Physikzentrum Bad Honnef, Germany (June-July, 2026).
I received financial support from the Wilhelm and Else Heraeus Foundation and the IDIL Graduate Program, Université de Montpellier, for travel and accommodation.
3. Polymer dynamics with blockwise mobility heterogeneity
Independent research
Different parts of a polymer can have different mobilities due to variations in local friction or crowding, even when their intrinsic properties are identical. Here, I investigate how this heterogeneity affects relaxation, diffusion and stretching of a Gaussian polymer in two dimensions through two complementary models.
First, I study a diblock copolymer using discrete Monte Carlo simulations on a two-dimensional square lattice, where I assign different update rates to the two blocks while keeping their bond-preserving movement rules unchanged. The faster-updated block moves farther at early and intermediate times, but the center-of-mass diffusion of the whole chain retains the Rouse scaling - the diffusion coefficient is inversely proportional to chain length, with a modified prefactor. A coarse-grained Rouse argument explains this scaling and extends it to any fixed number of blocks, provided their fractions of the total chain length and relative update rates remain fixed.
I then make the friction differences explicit in a continuous Langevin model and put the polymer in a Batchelor-Kraichnan random-flow field. Without flow, I recover the main dynamical trends observed in the Monte Carlo simulations. Under flow, the higher-friction (less mobile) block stretches more, and this imbalance persists when flow strength is matched relative to each chain’s longest relaxation time. Mode analysis explains this rather counterintuitive result, because random strain preferentially amplifies the slowest relaxation mode, whose spatial shape changes with friction heterogeneity.
All current results concern ideal Gaussian polymers, which limits their direct applicability to real chains. Future directions include extending the study to self-avoiding chains, three-dimensional chains, finite-extension springs and more realistic flows, to better describe polymers in heterogeneous environments.
Discrete Monte Carlo study:
➤ Preprint: arXiv:2606.04002
➤ Code and data: GitHub repository
Continuous random-flow study:
➤ Preprint: arXiv:2609.31707
➤ Code and data: GitHub repository
Selected papers
1. Linda Delimi, Arpan Dey, Jean-Charles Walter. Phase diagram of a semiflexible magnetic polymer in three dimensions. 2026. arXiv:2610.08958.
2. Arpan Dey. Blockwise friction heterogeneity redistributes stretching in a 2D Gaussian polymer under Batchelor-Kraichnan random flow. 2026. arXiv:2609.31707.
3. Arpan Dey. Collective drift and pinning in active rotator networks with Kuramoto coupling and mixed-sign feedback disorder. 2026. arXiv:2606.10032.
4. Arpan Dey. Mobility heterogeneity in a 2D Gaussian lattice polymer: a dynamic Monte Carlo study. 2026. arXiv:2606.04002. Accepted for publication in Polymer Science, Series A.
5. Arpan Dey. Is statistical mechanics just a tool? 2026. PhilSci Archive: 31218.
6. Arpan Dey. Nonlinear dynamics of dyads with self-regulating internal states and nonreciprocal, time-decaying interactions. 2026. Research Square: rs-9390873.
Selected presentations
1. Linda Delimi, Arpan Dey. Phase diagram of a semiflexible magnetic polymer in three dimensions. Talk. Supercoiling @ Sète (scientific retreat), Sète, France. November, 2026. Upcoming.
2. Arpan Dey. Collective drift and pinning in Kuramoto-coupled active rotator networks with mixed-sign local feedback. Poster and flash talk. 860th WE-Heraeus seminar: Half a Century of the Kuramoto Model: Explaining Emergent Order in Time and Space, Physikzentrum Bad Honnef, Germany. June-July, 2026. (Poster)
3. Linda Delimi, Arpan Dey. How stiffness and interactions shape the structure of magnetic polymers. Talk. ANR project meeting on Bacterial DNA Segregation (BaDS), Laboratoire Charles Coulomb, Montpellier, France. April, 2026.
4. Linda Delimi, Arpan Dey, Jean-Charles Walter. Phase diagram and ground states of the semiflexible magnetic polymer in the zero-field limit. Poster. First annual meeting of GDR ADN-Phys (Architecture and Dynamics of the Nucleus and Genomes), ENS de Lyon, Lyon, France. March-April, 2026.
5. Arpan Dey. Dyadic emotional modeling: a nonlinear dynamics approach. Poster and talk. International School on Urban Physics for Environmental Research (organized by Université de Montpellier, Universität Stuttgart and Technische Universität Wien), ENSCM, Montpellier, France. January, 2026. (Slides)
6. Arpan Dey. Statics and dynamics of an interacting polymer: application to bacterial DNA segregation. Presentation. Bibliographic project presentations, IDIL Graduate Program (Physics track), Université de Montpellier, Montpellier, France. January, 2026. (Slides)
Supervisors: Jean-Charles Walter, Andrea Parmeggiani, Linda Delimi.
7. Arpan Dey. Assessing large language model reasoning on ordinary differential equations. Presentation. Non-core unit on AI, IDIL Graduate Program, Université de Montpellier, Montpellier, France. December, 2025. (Slides)
Supervisors: Ovidiu Radulescu, Gabriele Orlando.
8. Arpan Dey. Exploring synchronized oscillations in Kuramoto-type oscillators with nonlinear feedback. Presentation. Summer research project, Institute of Mathematical Sciences, Chennai, India. June, 2025. (Slides)
Supervisor: Sitabhra Sinha.
9. Arpan Dey. Path integrals, uncertainty, entropy and information (100 years of quantum mechanics). Talk. Quantum foundations summer school (organized by Bhaktivedanta Institute, Kolkata and Centre for Development of Advanced Computing, Patna), Kolkata, India. June, 2025. (Slides)
10. Arpan Dey. Path integral formulation of quantum mechanics. Presentation. Undergraduate dissertation project, St Xavier’s College, Kolkata, India. June, 2025.
Supervisor: Tanaya Bhattacharyya.
11. Arpan Dey. Assembly Theory and the Evolution of Complex Systems. Talk. Spectrum (annual fest of the department of physics), St Xavier’s College, Kolkata, India. March, 2024. (Slides)
12. Arpan Dey. Emergence and Consciousness. Virtual presentation. Summer Opportunity for Academic Research (Laney Graduate School, Emory University). August, 2023. (Slides)
Selected reports, monographs and book chapters
1. Arpan Dey. Statics and dynamics of an interacting polymer: application to bacterial DNA segregation. Bibliographic project, IDIL Graduate Program, Université de Montpellier. Supervisors: Jean-Charles Walter, Andrea Parmeggiani, Linda Delimi. 2026. (Read)
2. Arpan Dey. Monte Carlo simulations of polymer dynamics on a 2D lattice: Rouse constraints, heterogeneous update rules and emergent global behavior. 2025. (Read)
3. Arpan Dey. Beyond quantum mechanics: black holes, information, unification, extra dimensions and the future of theoretical physics. 2025. (Read)
4. Arpan Dey. Magnetization in the 1D Ising model and the Metropolis algorithm: a glimpse into statistical physics and Monte Carlo simulations. 2025. (Read)
5. Arpan Dey. Path integral formulation of quantum mechanics. Undergraduate dissertation project, St Xavier’s College, Kolkata. Supervisor: Tanaya Bhattacharyya. 2025. (Read)
6. Arpan Dey. Investigations on the fundamental domain of the modular group. Summer research project, Physical Research Laboratory, Ahmedabad. Supervisor: Ketan Patel. 2024. (Read)
7. Fabeha Shafaat, Roberto Parisi, Arpan Dey, Nipun Gorantla, Fahad Hassan Shah. Properties and biomedical applications of graphene-based nanotechnologies. Book chapter in Nanotherapeutic Strategies and New Pharmaceuticals (Part 1), Bentham Science Publishers. 2021. (DOI: 10.2174/9789815036694121010007)
Selected essays and magazine articles
1. Boltzmann’s past hypothesis: why yesterday was special? Horizons Issue 1 (a publication of Niharika, the astronomy and astrophysics club, Indian Association for the Cultivation of Science, Kolkata). 2026. (Read, pg. 65)
2. The method in Nature’s madness: synchronization, collective behavior and phase transitions. Pebbles Vol 18 (annual magazine of the Science Association, St Xavier’s College, Kolkata). 2026. (Read, pg. 66)
3. Mathematics: the future of physics? Pebbles Vol 17 (annual magazine of the Science Association, St Xavier’s College, Kolkata). 2025. (Read, pg. 140)
4. Complexity: the next big thing in physics. 2024. (Read)
5. Science, religion and the search for truth. 2024. (Read)
6. The limits of metaphysics. 2022. (Read)
7. A discussion on the theory of everything. Horizon Vol 14 (annual magazine of the physics department, St Xavier’s College, Kolkata). 2022. (Read, pg. 59)
Mentoring and science outreach
Beyond my own research, I try to help younger students explore scientific questions and develop their ideas. Alongside informal interactions with students, I have taken on structured mentoring roles through the Xaverian Astronomical Society at St Xavier’s College, Kolkata, in 2025 and the Young Scientists Journal Research Program in 2026. Through the latter, I guided four high-school students through a one-month research experience, helping them develop their own research question in physics, work through difficulties and gain a first exposure to how research unfolds. My introductory slides outline the program’s structure and approach.
Projects I have mentored include:
➤ Understanding the black hole information paradox from a quantum information perspective
➤ Understanding the holographic principle and the Ryu-Takayanagi conjecture through simplified toy models of AdS/CFT duality
➤ Numerical investigation of phase dynamics of Adler oscillator networks
➤ Conceptual exploration of entropy, irreversibility and the arrow of time
The Journal of Young Physicists
The same interest in helping students take their ideas seriously led me to create the Journal of Young Physicists (JYP) on 1 July 2020, when I was sixteen. It began without any institutional backing or funding, as a small student blog. Since then, it has grown through the collective work of volunteer reviewers and contributors, connecting more than 30 young physics enthusiasts around the world and publishing over 140 articles (as of October, 2026).
JYP is a student-led, not-for-profit platform, free to submit to, publish in and read. We publish accessible explainers and conceptual essays alongside reviews, pedagogical reports, original research and computational or experimental studies. Our scope includes physics and related interdisciplinary areas, from complex systems and medical physics to AI and environmental science.
The plot on the right shows our publication history since 2020 (as of 17 October 2026). The early high publication count largely consisted of explainers and blogs, reviewed under less stringent editorial standards. The recent rise includes more rigorous research articles despite substantially stricter review, plagiarism screening and screening of AI-generated material. These numbers therefore reflect changes in both publication volume and the quality of work that we publish. We aim to maintain these standards while remaining accessible to young contributors and offering useful feedback even when submissions are rejected.
I began these initiatives because I know what it feels like to have genuine curiosity dismissed simply because you are young. That experience still shapes my approach to mentoring and JYP: Physics does not begin with permission, but with a question and the refusal to stop exploring it.
The Journal of Young Physicists:
Selected interviews, Q&As and features
1. The journey of a young physicist. STEMz Perspectives (Young Scientists Journal science podcast), hosted by Mayank Dora. 2024. (Listen)
2. Interview with an aspiring physicist. Travelling through pages (YouTube), hosted by Aaradhana Umesh. 2023. (Watch)
3. A comprehensive discussion on the most exciting topics in physics. The Journal of Young Physicists, an extended written Q&A on physics for the general audience, compiled by me. 2023. (Read)
4. ‘Dey’light at the end of a quantum tunnel as teen physicist Arpan explores consciousness. Global Indian, written by Darshana Ramdev. 2022. (Read)
5. All that matters is physics. The First Step, hosted by Hasini Lakshminarayanan. 2022. (Read)
6. Young author Arpan Dey talks about his book Our Physics So Far. The Literature Times. 2021. (Read)
Interviews with leading physicists and authors
1. A discussion on the physics of life with Apratim Chatterji of IISER Pune. Arpan D (YouTube). 2025. (Watch)
2. An interview on quantum foundations and theoretical physics with Tejinder Singh of TIFR Mumbai. The Journal of Young Physicists. 2025. (Read)
3. An interview with Paul Halpern, author of Einstein’s Dice and Schrödinger’s Cat. The Journal of Young Physicists. 2023. (Read)
4. An interview with Leonard Mlodinow, author of The Grand Design (with Stephen Hawking). The Journal of Young Physicists. 2023. (Read)
5. An interview with John Horgan, author of The End of Science. The Journal of Young Physicists. 2023. (Read)
6. In conversation with Edward Witten on fundamental physics. Interviewed for my book Our Physics So Far. 2020.
Early writing
An archive of my early articles and essays, retained as a record of how my interests developed. Some of these articles contain speculative arguments or scientific inaccuracies and do not reflect my current understanding.
1. Chaos theory and consciousness. 2021. (Read)
2. Paradoxes and the fundamental nature of reality. 2021. (Read)
3. The Higgs boson and the creation of mass. 2020. (Read)
4. Beyond the brain: neuroscience, human consciousness and immortality. 2020. (Read)
5. Investigations on isotopic elements in terms of quarks. 2020. (Read)
6. Can the de Broglie relation be modified for accommodating relativistic modifications in the Schrödinger equation? 2020. (Read)
7. A conceptual design for improving aircraft take-off efficiency. 2020. (Read)
Questions that keep me up at night
Alongside the more specific problems in my research, there are broader scientific questions I keep returning to. Some of these questions can be approached through physical models, while others raise more foundational questions about what a model even is, and what counts as knowledge or explanation. I list a few of these questions below.
➤ Time, entropy and information: Why does our universe have an arrow of time? What roles do its initial conditions, quantum mechanics, entropy and information play in the explanation?
➤ Mathematics and reality: Why are mathematical structures so effective at describing the physical world? Do they simply describe physical laws, or can they also help explain why those laws take the form they do?
➤ Quantum foundations: What can we establish about the reality behind quantum mechanics, beyond its predictions? Which differences between interpretations can be tested, and which remain philosophical?
➤ Emergence and consciousness: How far can microscopic laws explain the behavior of complex systems, even if only in principle? Can they also account for subjective experience? (Personally, I lean toward consciousness emerging from physical processes in the brain, but that leaves a great deal to understand. There is also something strange about using consciousness to understand consciousness - like trying to look at your own eyes without a mirror!)
➤ Physical laws and contingency: Physics models the world through cause-and-effect relations (such as equations of motion) or optimization principles (such as free-energy minimization or entropy maximization), but physics does not say anything about the real world directly. (An apple does not fall because of Newton’s law of gravitation; Newton’s law simply provides a fairly accurate model that describes this behavior.) So, how can we distinguish what is necessary about the world itself from what follows only from our models, their assumptions and particular initial conditions?
These questions also bring me back to two principles I try to follow in research (and in life):
➤ Keep asking questions. A question does not need to sound impressive to be worth asking. Following an apparently simple “why” can expose a gap in your understanding, or lead you to something nobody yet knows.
➤ Remember the scope of your lens. If you only count integers, you miss everything between them. That is fine when integers are all you need. With a model or framework, too, the important thing is to remember what it includes, what it leaves out, and whether those omissions matter for the question you are asking.
Snapshots from an ongoing journey
➤ This page was last updated on 17 October 2026.