About

Zvi Bern is a distinguished member of the theoretical physics community, recognized for his significant contributions to the field. He was inducted into the National Academy of Sciences on April 25 in Washington DC, highlighting his prominence in the scientific community. His work has been acknowledged with awards such as the 2026 Best Paper Frontiers of Science Award, which he received along with Mikhail Solon for their paper on 'Black Hole Binary Dynamics from the Double Copy and Effective Field Theory.' Bern's research focuses on advancing the understanding of fundamental physical laws through mathematical models and theoretical frameworks, contributing to the broader goals of the Bhaumik Institute for Theoretical Physics at UCLA. His efforts have helped shape the direction of research in theoretical particle physics and related areas.

Research topics

• Physics
• Computer Science
• Mathematical physics
• Mathematics
• Quantum mechanics
• Optics
• Acoustics
• Quantum electrodynamics
• Arithmetic
• Materials science

Selected publications

• Classical Gravitational Scattering from the Ultraviolet and the Absence of Calabi-Yau Integrals in the Conservative Sector at $O(G^5)$

  arXiv (Cornell University) · 2026-03-16

  articleOpen access1st authorCorresponding

  We explain why Calabi-Yau and complete elliptic integrals do not contribute to conservative observables at fifth post-Minkowskian order, despite appearing in intermediate steps. At even loop orders, conservative contributions are tied to terms proportional to the logarithm of the momentum transfer, which in dimensional regularization arise from singular regions. We show that in the classical limit, the integral classes responsible for Calabi-Yau and complete elliptic behavior are absent from the ultraviolet singular structures that generate the required logarithm. This perspective also suggests alternative strategies for analyzing the classical limit of multiloop integrals in the conservative sector at even loop orders.

  PublisherOA PDF

• Second-Order Self-Force Potential-Region Binary Dynamics at O(G⁵) in Supergravity

  Repository for Publications and Research Data (ETH Zurich) · 2026-02-27

  otherOpen access1st authorCorresponding

  We compute the potential-graviton contributions to the conservative scattering angle of two nonspinning bodies in maximal supergravity at fifth order in Newton’s constant, including second-order self-force effects. Our goal is to tackle the challenging integrals arising at this order in Einstein gravity, but within the technically simpler framework of supergravity. The calculation employs the scattering-amplitude framework, effective field theory, and multiloop integration techniques based on integration by parts and differential equations. The final result is expressed as a series expansion around the static limit, thereby avoiding the explicit evaluation of intricate special functions. This series solution for the master integrals applies, as well, to the corresponding computation in general relativity. Remarkably, we observe nontrivial cancellations among contributions associated with Calabi-Yau integrals, alongside a distinct contribution governed by a Heun differential equation.

  PublisherDOI

• Classical Gravitational Scattering from the Ultraviolet and the Absence of Calabi-Yau Integrals in the Conservative Sector at $O(G^5)$

  arXiv (Cornell University) · 2026-03-16

  preprintOpen access1st authorCorresponding

  We explain why Calabi-Yau and complete elliptic integrals do not contribute to conservative observables at fifth post-Minkowskian order, despite appearing in intermediate steps. At even loop orders, conservative contributions are tied to terms proportional to the logarithm of the momentum transfer, which in dimensional regularization arise from singular regions. We show that in the classical limit, the integral classes responsible for Calabi-Yau and complete elliptic behavior are absent from the ultraviolet singular structures that generate the required logarithm. This perspective also suggests alternative strategies for analyzing the classical limit of multiloop integrals in the conservative sector at even loop orders.

  PublisherDOI

• Observables and unconstrained spin tensor dynamics in general relativity from scattering amplitudes

  Journal of High Energy Physics · 2025-12-10

  articleOpen access

  A bstract In a previous Letter, we showed that physical scattering observables for compact spinning objects in general relativity can depend on additional degrees of freedom beyond those described by the spin vector, which can be packaged into an unconstrained spin tensor. In this paper, we provide further details on the physics of these additional degrees of freedom, whose commutation relations and Poisson brackets are inherited from the underlying Lorentz symmetry, and on their consequence on observables. In particular, we give the waveform at leading order in Newton’s constant and up to second order in the components of the spin tensor, and the conservative impulse, boost and spin kick, exhibiting spin magnitude change, through next-to-leading-order in Newton’s constant and third order in the components of the spin tensor. We provide explicit examples — a Newtonian two-particle bound system and a certain black-hole solution in an exotic matter-coupled gravitational theory — that exhibit these degrees of freedom and are described by our four-dimensional and worldline field theories. We also discuss connections between these degrees of freedom and dynamical worldline multipole moments. We construct effective two-body Hamiltonians, we demonstrate explicitly that the extra degrees of freedom beyond the spin vector are necessary to describe the complete dynamics, and we explicitly remove certain unphysical singularities. Moreover, we show that the previously proposed eikonal (or radial action) formula correctly captures observables derived from the classical Hamiltonian. Finally, we comment on possible descriptions of the additional degrees of freedom from the perspective of Goldstone’s theorem.

  PublisherOA PDFDOI

• Global bases for nonplanar loop integrands, generalized unitarity, and the double copy to all loop orders

  Journal of High Energy Physics · 2025-06-12 · 6 citations

  articleOpen access1st authorCorresponding

  A bstract We introduce a constructive method for defining a global loop-integrand basis for scattering amplitudes, encompassing both planar and nonplanar contributions. Our approach utilizes a graph-based framework to establish a well-defined, non-redundant basis of integrands. This basis, constructed from a chosen set of non-redundant graphs together with a selection of irreducible scalar products, provides clear insights into various physical properties of scattering amplitudes and proves useful in multiple contexts, such as on-shell Ward identities and manifesting gauge-choice independence. A key advantage of our integrand basis is its ability to streamline the generalized unitarity method. Specifically, we can directly read off the coefficients of basis elements without resorting to ansätze or solving linear equations. This novel approach allows us to lift generalized unitarity cuts — expressed as products of tree amplitudes — to loop-level integrands, facilitating the use of the tree-level double copy to generate complete gravitational integrands at any loop order. This method circumvents the difficulties in identifying complete higher-loop-order gauge-theory integrands that adhere to the color-kinematics duality. Additionally, our cut-based organization is well-suited for expansion in hard or soft limits, aiding in the exploration of ultraviolet or classical limits of scattering amplitudes.

  PublisherOA PDFDOI

• Conservative Spin-Magnitude Change in Orbital Evolution in General Relativity

  Physical Review Letters · 2025-03-14 · 14 citations

  articleOpen access

  We show that physical scattering observables for compact spinning objects in general relativity can depend on additional degrees of freedom in the spin tensor beyond those described by the spin vector alone. The impulse, spin kick, and leading-order waveforms exhibit such a nontrivial dependence. A signal of this additional structure is the change in the magnitude of the spin vector under conservative Hamiltonian evolution, similar to our previous studies in electrodynamics. These additional degrees of freedom describe dynamical mass multipoles of compact objects and decouple for black holes. We also show that the conservative impulse, spin kick, and change of the additional degrees of freedom are encoded in the eikonal phase.

  PublisherOA PDFDOI

• Scattering Amplitudes and Conservative Binary Dynamics at $O(G^5)$ without Self-Force Truncation

  arXiv (Cornell University) · 2025-12-29

  articleOpen access1st authorCorresponding

  We compute the complete potential-graviton contributions to the conservative radial action and scattering angle for two non-spinning bodies in general relativity, accurate through fifth order in Newton's constant and including second-order self-force (2SF) effects. The calculation is carried out in the scattering-amplitude framework, combining the double copy, effective field theory, and multi-loop integration techniques based on integration by parts and differential equations. To address a major computational bottleneck, we develop improved integration-by-parts algorithms that render calculations at this order tractable. The post-Minkowskian amplitude is presented as a series expansion, following the strategy used earlier in maximal supergravity. For the first self-force sector, which involves only polylogarithmic functions, we also provide a closed-form analytic expression. For the second self-force sector, as in earlier supergravity work, we find nontrivial cancellations among contributions related to integrals supported on Calabi-Yau geometry.

  PublisherOA PDF

• Scattering Amplitudes and Conservative Binary Dynamics at $O(G^5)$ without Self-Force Truncation

  Open MIND · 2025-12-29

  preprint1st authorCorresponding

  We compute the complete potential-graviton contributions to the conservative radial action and scattering angle for two non-spinning bodies in general relativity, accurate through fifth order in Newton's constant and including second-order self-force (2SF) effects. The calculation is carried out in the scattering-amplitude framework, combining the double copy, effective field theory, and multi-loop integration techniques based on integration by parts and differential equations. To address a major computational bottleneck, we develop improved integration-by-parts algorithms that render calculations at this order tractable. The post-Minkowskian amplitude is presented as a series expansion, following the strategy used earlier in maximal supergravity. For the first self-force sector, which involves only polylogarithmic functions, we also provide a closed-form analytic expression. For the second self-force sector, as in earlier supergravity work, we find nontrivial cancellations among contributions related to integrals supported on Calabi-Yau geometry.

  DOI

• Observables and Unconstrained Spin Tensor Dynamics in General Relativity from Scattering Amplitudes

  Archive ouverte UNIGE (University of Geneva) · 2025-03-05

  preprintOpen access

  In a previous Letter, we showed that physical scattering observables for compact spinning objects in general relativity can depend on additional degrees of freedom in the spin tensor beyond those described by the spin vector alone. In this paper, we provide further details on the physics of these additional degrees of freedom, whose commutation relations and Poisson brackets are inherited from the underlying Lorentz symmetry, and on their consequence on observables. In particular, we give the waveform at leading order in Newton's constant and up to second order in the components of the spin tensor, and the conservative impulse, boost and spin kick, exhibiting spin magnitude change, through next-to-leading-order in Newton's constant and third order in the components of the spin tensor. We provide explicit examples -- a Newtonian two-particle bound system and a certain black-hole solution in an exotic matter-coupled gravitational theory -- that exhibit these degrees of freedom and are described by our four-dimensional and worldline field theories. We also discuss connections between these degrees of freedom and dynamical worldline multipole moments. We construct effective two-body Hamiltonians, we demonstrate explicitly that the extra degrees of freedom beyond the spin vector are necessary to describe the complete dynamics, and we explicitly remove certain unphysical singularities. Moreover, we show that the previously proposed eikonal (or radial action) formula correctly captures observables derived from the classical Hamiltonian. Finally, we comment on possible descriptions of the additional degrees of freedom from the perspective of Goldstone's theorem.

  PublisherDOI

• Second-order self-force potential-region binary dynamics at $O(G^5)$ in supergravity

  ArXiv.org · 2025-09-22

  preprintOpen access1st authorCorresponding

  We compute the potential-graviton contributions to the conservative scattering angle of two non-spinning bodies in maximal supergravity at fifth order in Newton's constant, including second-order self-force effects. Our goal is to tackle the challenging integrals arising at this order in Einstein gravity, but within the technically simpler framework of supergravity. The calculation employs the scattering-amplitude framework, effective field theory, and multi-loop integration techniques based on integration by parts and differential equations. The final result is expressed as a series expansion around the static limit, thereby avoiding the explicit evaluation of intricate special functions. This series solution for the master integrals applies, as well, to the corresponding computation in general relativity. Remarkably, we observe nontrivial cancellations among contributions associated with Calabi-Yau integrals, alongside a distinct contribution governed by a Heun differential equation.

  PublisherOA PDFDOI

Frequent coauthors

• Lance J. Dixon

  Imperial College London

  649 shared

• F. Febres Cordero

  Florida State University

  585 shared

• D. Maître

  STMicroelectronics (India)

  548 shared

• H. Ita

  University of Zurich

  544 shared

• David A. Kosower

  CEA Paris-Saclay

  540 shared

• Kemal Ozeren

  360 shared

• Stefan Hoeche

  293 shared

• David A Kosower

  Centre National de la Recherche Scientifique

  175 shared

Awards & honors

• 2026 Laureate of the New Horizons in Physics Prize
• 2026 Best Paper Frontiers of Science Award