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Theoretical Physicist | Scientific Modeling & Simulation | AI & Quantitative Analysis Expert

Profile Summary

I am an Assistant Professor of Theoretical Physics with a strong background in mathematical modeling, complex systems, and computational analysis. I specialize in translating advanced physical theories into practical, implementable models for research and industry applications. My expertise includes: * Physics-based modeling and simulation (deterministic and stochastic systems) * Numerical methods and scientific computing (Python) * Statistical physics and complex systems * AI model evaluation and reasoning validation (LLMs) * Semiconductor and graphene-based systems (emerging technologies) I have contributed to peer-reviewed research and worked as a STEM expert in AI training, focusing on evaluating and improving model reasoning in mathematics and physics. I am particularly interested in collaborating with startups, R&D teams, and organizations that require rigorous scientific thinking, high-level modeling, or technical validation of complex ideas. I bring a combination of theoretical depth, computational skill, and practical problem-solving. I am open to long-term collaborations and advisory roles for deep-tech and R&D projects.

Subject Matter Expertise

• ☆ Data Analysis
• ☆ Machine Learning
• ☆ Statistics
• ☆ Applied Statistics
• ☆ Electromagnetism
• ☆ Applied Mechanics
• ☆ Theoretical Mechanics
• ☆ Fluid Dynamics
• ☆ Statistical Mechanics
• ☆ Thermodynamics
• ☆ Particle Physics
• ☆ Quantum Mechanics
• ☆ Theoretical Physics
• ☆ Computational Physics
• ☆ Applied Physics
• ☆ Relativity Theory
• ☆ Applied Mathematics
• ☆ Mathematical Models
• ☆ Computational Sciences
• ☆ Mathematical Physics
• ☆ Differential Equations
• ☆ Python

Services

• Writing
• Research
• Consulting
• Data & AI
• Product Development

Writing Technical Writing

Research Scientific and Technical Research

Consulting Scientific and Technical Consulting

Data & AI Predictive Modeling, Statistical Analysis, Algorithm Design-ML

Product Development Concept Development

Work Experience

Assistant Professor

University of Zagreb

March 2026 - Present

System developer

Ericsson

April 2023 - February 2026

Data Scientist

Scoop Technologies

July 2022 - March 2023

Postdoctoral Researcher

University of Zagreb, Faculty of Science

December 2016 - June 2022

Graduate Research Assistant / Research Assistant

Rudjer Boskovic Institute

December 2010 - December 2016

Education

Doctorate

University of Zagreb

February 2011 - July 2016

Master of Science

University of Zagreb

October 2005 - September 2010

Certifications

• Certification details not provided.

Publications

JOURNAL ARTICLE

Bruno Klajn, Roukaya Dekhil, Clifford Ellgen (2026). Finite path integrals on stochastic branched structures . Journal of Physics A: Mathematical and Theoretical.

Klajn, Bruno, Dekhil, Roukaya, Ellgen, Clifford(2026). Finite path integrals on stochastic branched structures . J.Phys.A. 59. (12). Microsoft.AspNetCore.Mvc.Localization.LocalizedHtmlString 125302.

Klajn, Bruno, Nikolić, Hrvoje(2025). Hidden momentum of composite bodies and magnetic dipoles .

Klajn, Bruno, Domazet, Silvije, Jukić, Dario, Buljan, Hrvoje(2021). Exactly solvable model for anyons with non-Abelian flux . Phys.Rev.A. 104. (5). Microsoft.AspNetCore.Mvc.Localization.LocalizedHtmlString 052217.

Bruno Klajn, Silvije Domazet, Dario Jukić, Hrvoje Buljan (2021). Exactly solvable model for anyons with non-Abelian flux . Physical Review A.

Klajn, Bruno, Smolic, Ivica (2021). Capacitance matrix revisited . ArXiv.

Klajn, B., Domazet, S., Jukić, D., Buljan, H.(2021). Exactly solvable model for anyons with non-Abelian flux . Physical Review A. 104. (5).

Smolic, I., Klajn, B.(2021). Capacitance Matrix Revisited . Progress in Electromagnetics Research B. 92. Microsoft.AspNetCore.Mvc.Localization.LocalizedHtmlString 1-18.

Klajn, Bruno, Smolić, Ivica(2021). Capacitance matrix revisited . PIER. 92. Microsoft.AspNetCore.Mvc.Localization.LocalizedHtmlString 1--18.

Bruno Klajn, Ivica Smolić (2021). CAPACITANCE MATRIX REVISITED . Progress In Electromagnetics Research B.

Bruno Klajn, Marija Todorić, Dario Jukić, Hrvoje Buljan(2020). Berry phase for a Bose gas on a one-dimensional ring . Physical Review A. 102. (1). American Physical Society ({APS})

Klajn, Bruno, Lunić, Frane, Todorić, Marija, Dubček, Tena, Jukić, Dario, Buljan, Hrvoje(2020). Exact solutions of a model for synthetic anyons in a noninteracting system . Phys.Rev.B. 101. (11). Microsoft.AspNetCore.Mvc.Localization.LocalizedHtmlString 115139.

Bruno Klajn, Frane Lunić, Marija Todorić, Tena Dubček, Dario Jukić, Hrvoje Buljan(2020). Exact solutions of a model for synthetic anyons in a noninteracting system . Physical Review B. 101. (11). American Physical Society ({APS})

Lunić, F., Todorić, M., Klajn, B., Dubček, T., Jukić, D., Buljan, H.(2020). Exact solutions of a model for synthetic anyons in a noninteracting system . Physical Review B. 101. (11).

Todorić, M., Klajn, B., Jukić, D., Buljan, H.(2020). Berry phase for a Bose gas on a one-dimensional ring . Physical Review A. 102. (1).

Klajn, Bruno, Dubček, Tena, Pezer, Robert, Buljan, Hrvoje, Jukić, Dario(2018). Quasimomentum distribution and expansion of an anyonic gas . Phys.Rev.A. 97. (1). Microsoft.AspNetCore.Mvc.Localization.LocalizedHtmlString 011601.

Bruno Klajn, Tena Dubček, Robert Pezer, Hrvoje Buljan, Dario Jukić (2018). Quasimomentum distribution and expansion of an anyonic gas . Physical Review A.

Dubček, T., Klajn, B., Pezer, R., Buljan, H., Jukić, D.(2018). Quasimomentum distribution and expansion of an anyonic gas . Physical Review A. 97. (1).

Klajn, Bruno, Dubcek, Tena, Pezer, Robert, Buljan, Hrvoje, Jukic, Dario (2018). Quasimomentum distribution and expansion of an anyonic gas . Physical Review A.

Klajn, Bruno, Duplancic, Goran(2017). Direct numerical approach to one-loop amplitudes . Phys.Rev.D. 95. (1). Microsoft.AspNetCore.Mvc.Localization.LocalizedHtmlString 016002.

G. Duplančić, B. Klajn (2017). Direct numerical approach to one-loop amplitudes . Physical Review D.

Duplancic, G., Klajn, B. (2017). Direct numerical approach to one-loop amplitudes . Physical Review D.

Duplančić, G., Klajn, B.(2017). Direct numerical approach to one-loop amplitudes . Physical Review D. 95. (1).

Bečirević, D., Duplančić, G., Klajn, B., Melić, B., Sanfillipo, F.(2016). Charmonia decay constants from the QCD lattice and QCD sum rules . Nuclear and Particle Physics Proceedings. 273-275. Microsoft.AspNetCore.Mvc.Localization.LocalizedHtmlString 1611-1617.

Klajn, Bruno, Bečirević, Damir, Duplančić, Goran, Melić, Blaženka, Sanfilippo, Francesco(2014). Lattice QCD and QCD sum rule determination of the decay constants of $\eta_c$, J/$\psi$ and $h_c$ states . Nucl.Phys.B. 883. Microsoft.AspNetCore.Mvc.Localization.LocalizedHtmlString 306--327.

Bruno Klajn, Damir Bečirević, Goran Duplančić, Blaženka Melić, Francesco Sanfilippo (2014). Lattice QCD and QCD sum rule determination of the decay constants of eta_c, J/psi and hc states . Nuclear Physics B.

Klajn, Bruno(2014). Exact high temperature expansion of the one-loop thermodynamic potential with complex chemical potential . Phys.Rev.D. 89. (3). Microsoft.AspNetCore.Mvc.Localization.LocalizedHtmlString 036001.

Bruno Klajn (2014). Exact high temperature expansion of the one-loop thermodynamic potential with complex chemical potential . Physical Review D.

Klajn, Bruno, Becirevic, Damir, Duplancic, Goran, Melic, Blazenka, Sanfilippo, Francesco (2014). Lattice QCD and QCD sum rule determination of the decay constants of η<i>_c</i>, <i>J</i>/ψ and <i>h_c</i>, states . Nuclear Physics B.

Bečirević, D., Duplančić, G., Klajn, B., Melić, B., Sanfilippo, F.(2014). Lattice QCD and QCD sum rule determination of the decay constants of ηc, J/ψ and h c states . Nuclear Physics B. 883. (1). Microsoft.AspNetCore.Mvc.Localization.LocalizedHtmlString 306-327.

Klajn, Bruno (2014). Exact high temperature expansion of the one-loop thermodynamic potential with complex chemical potential . Physical Review D.

Klajn, B.(2014). Exact high temperature expansion of the one-loop thermodynamic potential with complex chemical potential . Physical Review D Particles Fields Gravitation and Cosmology. 89. (3).

B Klajn, I Smolić (2013). Subtleties of invariance, covariance and observer independence . European Journal of Physics.

Klajn, B., Smolic, I. (2013). Subtleties of invariance, covariance and observer independence . European Journal of Physics.

Klajn, B., Smolić, I.(2013). Subtleties of invariance, covariance and observer independence . European Journal of Physics. 34. (4). Microsoft.AspNetCore.Mvc.Localization.LocalizedHtmlString 887-899.

Klajn, Bruno, Smolić, Ivica(2013). Subtleties of Invariance, Covariance and Observer Independence . Eur.J.Phys. 34. Microsoft.AspNetCore.Mvc.Localization.LocalizedHtmlString 887--899.

D. Jukić, B. Klajn, H. Buljan (2009). Momentum distribution of a freely expanding Lieb-Liniger gas . Physical Review A.

Jukic, D., Klajn, B., Buljan, H. (2009). Momentum distribution of a freely expanding Lieb-Liniger gas . Physical Review A.

Jukić, D., Klajn, B., Buljan, H.(2009). Momentum distribution of a freely expanding Lieb-Liniger gas . Physical Review A Atomic Molecular and Optical Physics. 79. (3).

Jukić, D., Klajn, B., Buljan, H. (2009). Momentum distribution of a freely expanding Lieb-Liniger gas . ArXiv.

OTHER

Klajn, B., Nikolić, H.(2025). Hidden momentum of composite bodies and magnetic dipoles . Arxiv.

Klajn, B., Nikolić, H.(2025). Hidden momentum of composite bodies and magnetic dipoles . Arxiv.

Klajn, B., Domazet, S., Jukić, D., Buljan, H.(2021). An exactly solvable model for anyons with non-Abelian flux . Arxiv.

Klajn, B., Domazet, S., Jukić, D., Buljan, H.(2021). An exactly solvable model for anyons with non-Abelian flux . Arxiv.

Todoric, M., Klajn, B., Jukic, D., Buljan, H.(2020). Berry phase for a bose gas on a one-dimensional ring . Arxiv.

Todoric, M., Klajn, B., Jukic, D., Buljan, H.(2020). Berry phase for a bose gas on a one-dimensional ring . Arxiv.

Smolić, I., Klajn, B.(2020). Capacitance matrix revisited . Arxiv.

Lunić, F., Todorić, M., Klajn, B., Dubček, T., Jukić, D., Buljan, H.(2019). Synthetic anyons in noninteracting systems . Arxiv.

Lunić, F., Todorić, M., Klajn, B., Dubček, T., Jukić, D., Buljan, H.(2019). Synthetic anyons in noninteracting systems . Arxiv.

Dubček, T., Klajn, B., Pezer, R., Buljan, H., Jukić, D.(2017). Quasimomentum distribution and expansion of an anyonic gas . Arxiv.

CONFERENCE PAPER

Dubcek, T., Klajn, B., Pezer, R., Buljan, H., Jukic, D.(2018). Quasimomentum Distribution and Free Expansion of an Anyonic Gas . 2018 Conference on Lasers and Electro Optics CLEO 2018 Proceedings.

Klajn, Bruno, Bečirević, Damir, Duplančić, Goran, Melić, Blaženka, Sanfillipo, Francesco(2016). Charmonia decay constants from the QCD lattice and QCD sum rules . Nucl.Part.Phys.Proc. 273-275. Microsoft.AspNetCore.Mvc.Localization.LocalizedHtmlString 1611--1617.

DISSERTATION THESIS

Klajn, Bruno(2016). Računanje jednopetljenih Feynmanovih dijagrama direktnom numeričkom metodom .