PaperPanorama
FAQ

Nuclear Theory·nucl-th

Thursday·April 9, 2026

10 papers—3 primary·7 cross-listed

All10Primary3Cross-lists7
  1. 01

    Relativistic Barnett effect and Curie law in a rigidly rotating free Fermi gas

    M. Abedlou Ahadi🇮🇷 · N. Sadooghi🇮🇷

    By combining methods from thermal field theory and statistical mechanics, we reexamine the spin polarization caused by the relativistic Barnett effect in a rigidly rotating Fermi gas. We determine the pressure of this medium and show that it depends on an effective chemical potential, which includes contributions from orbital angular momentum-rotation and spin-rotation coupling. We introduce a specific regularization scheme to sum over the angular momentum quantum numbers. As a result, the thermal pressure and all thermodynamic quantities are separated into two parts that differ only in the spin fugacities of spin-up and spin-down fermions. We calculate the Fermi energy for both components and show that the Fermi energy of the spin-down fermions is lower than that of the spin-up ones. This difference arises from the spin-rotation coupling and leads to a spin polarization consistent with the Barnett effect. In particular, we introduce the spin-chemicorotational ratio , which adjusts the spin polarization of the Fermi gas. Here, and represent the angular velocity and chemical potential at zero temperature, respectively. The factor accounts for the fermion's spin. We explore the temperature dependence of and , while assuming that the number of spin-up and spin-down fermions remains temperature independent. Our findings indicate that the spin-down component of the rotating Fermi gas dilutes at lower temperatures compared to the spin-up component. Additionally, we calculate the magnetic susceptibility arising from the Barnett magnetization and demonstrate that it is proportional to the moment of inertia of the rotating Fermi gas. Finally, we prove that exhibits a behavior in the high-temperature limit, similar to the Curie law of paramagnetism.

    nucl-thcond-mat.quant-gashep-ph0 citations
  2. 02

    How acausal equations emerge from causal dynamics

    Lorenzo Gavassino🇬🇧

    We construct a causal and covariantly stable kinetic model whose spectrum at real wavenumbers reproduces any rest-frame stable dissipative dispersion relation via suitable initialization of the microscopic degrees of freedom. Macroscopic observables can therefore obey arbitrary linear evolution equations (including forms that would be acausal if taken as fundamental), while the underlying dynamics remains causal, and all apparent propagation is encoded in the initial data. This provides an explicit counterexample to the idea that microscopic causality alone constrains the analytic form of dispersion relations at real . In particular, bounds on transport coefficients based solely on the analytic structure of , such as the hydrohedron bounds, require additional assumptions about the region in the complex -plane where corresponds to physical modes.

    nucl-thhep-thmath-phmath.MP4 citations
  3. 03

    Nuclear giant resonances from first principles

    Sonia Bacca · Francesco Marino · Andrea Porro

    This chapter presents an ab initio perspective on giant resonances in atomic nuclei and surveys the principal theoretical frameworks that aim to describe these collective excitations from first principles. While the study of nuclear giant resonances has traditionally been dominated by the energy density functional approach, recent years have witnessed the development of advanced many-body approaches grounded directly in realistic nuclear interactions, namely, Hamiltonians that reproduce nucleon-nucleon phase shifts and accurately describe the binding energies of light nuclei. Within this modern framework, we review the main many-body methods currently used to compute nuclear response functions. These include the random phase approximation, the Lorentz integral transform coupled-cluster theory, the projected generator-coordinate method, and the self-consistent Green's functions approach. After giving a general conceptual and historical overview of giant-resonance phenomena, we outline the theoretical foundations and computational implementations of each method. We conclude with a critical comparison of their predictions for selected benchmark nuclei, O and Ca, emphasizing points of agreement and divergence, while maintaining a close connection to the relevant experimental observables.

    nucl-th5 citations

Affiliations

first authorsco-authorsvia INSPIRE