Nuclear Theory·nucl-th

Tuesday·May 6, 2025

18 papers—13 primary·5 cross-listed

14
[Submitted on 2 May 2025] (cross-list from astro-ph.HE)
Connecting afterglow light curves to the GRB central engine
Muhammed Diyaddin Ilhan · Kai Schwenzer
Gamma ray burst (GRB) afterglow light curves have the potential to inform us about presently unobserved stages in the aftermath of a neutron star merger. Using numerical simulations of short GRB afterglows we obtain an approximate quantitative connection between key aspects of the emission mechanism and the shapes of the resulting light curves. Employing simple, but efficient, parameterizations of the light curve based on a broken power law in terms of physical parameters, fitted to a large dataset of synthetic light curves, we apply basic machine learning techniques to determine the approximate connection between key input parameters of the forward shock model and the light curve parameters. Solving then the inverse problem, we find that the strength of the central engine can be reasonably accurately estimated even with very limited information. In particular, merely the position of jet-break in the on-axis, respectively the maximum in the off-axis light curve determines the kinetic energy at the tens of percent level.
Comments:
12 pages, 4 figures
Subjects:
High Energy Astrophysical Phenomena (astro-ph.HE); General Relativity and Quantum Cosmology (gr-qc); Nuclear Theory (nucl-th)
arXiv:
2505.01158 [pdf]
0 citations
15
[Submitted on 3 May 2025] (cross-list from hep-lat)
Realization of all-to-all fermion propagator for the first principle high accuracy strong interaction prediction
Zhi-Cheng Hu🇨🇳 · Ji-Hao Wang🇨🇳 · Xiangyu Jiang🇨🇳 · Liuming Liu🇨🇳 · Shi-Hao Su🇨🇳 · Peng Sun🇨🇳 · Yi-Bo Yang🇨🇳
We propose a ``blending" algorithm that projects the all-to-all fermion propagator onto spatial low-frequency modes (LFM) combined with a stochastic estimate of spatial high-frequency modes (SHFM) at each time slice. This approach enables the calculation of arbitrary-point correlation functions for arbitrary hadron states in strongly interacting quantum field theories (QFT) with fermions, such as quantum chromodynamics (QCD). Specifically, LFM allows the construction of spatially extended hadron states below a certain energy threshold by diagonalizing multi-fermion interpolation fields. Meanwhile, the local interactions required for N-point correlation functions in QFT can be approximated in an unbiased manner through a reweighted summation of both LFM and SHFM contributions. To demonstrate the efficiency of this algorithm, we obtained {\color{black} $g_{A}^{u} = 0.895 (15)$ , $g_{A}^{d} = - 0.338 (15)$ , $g_{A}^{s} = - 0.0245 (72)$ , $g_{A}^{u + d + s} = 0.533 (28)$ and $g_{A}^{u - d} = 1.2339 (43)$ } for nucleon at $m_{π} = 300$ MeV and $a = 0.077$ fm using 40 configurations. The consistency check of the pion electric form factor and charge radius derived from 3-point and 4-point correlation functions is also provided.
Comments:
20 pages, 15 figures, some of statements updated
Subjects:
High Energy Physics — Lattice (hep-lat); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2505.01719 [pdf]
3 citations
16
[Submitted on 3 May 2025] (cross-list from hep-th)
Chiral anomaly from (anomalous) spin hydrodynamics
Jay Armas🇳🇱 · Giorgos Batzios🇳🇱
We show that the low energy fluctuations of spinning black Dp branes are described by a theory of spin hydrodynamics on a spacetime $M_{p + 1} \times T^{n + 2}$ in which the fluid is flowing on $M_{p + 1}$ and spinning on $T^{n + 2}$ . Focusing on the hydrodynamic regime of $N = 4$ supersymmetric Yang-Mills theory, we provide a geometric interpretation of the R-current anomaly in terms of a gravitational anomaly from the ten-dimensional point of view. This follows from the holographic duality between a spinning fluid in ten dimensions and an anomalous chiral fluid in four dimensions. We comment on the relations between the theory of spin hydrodynamics introduced here and other theories of spin hydrodynamics in the context of heavy-ion collisions.
Comments:
v1:11pp, dedicated to the memory of Umut Gürsoy
Subjects:
High Energy Physics — Theory (hep-th); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2505.01843 [pdf]
PRD(2026)·3 citations
17
[Submitted on 5 May 2025] (cross-list from hep-th)
Unified exact WKB framework for resonance -- Zel'dovich/complex-scaling regularization and rigged Hilbert space
Okuto Morikawa🇯🇵 · Shoya Ogawa🇯🇵
We develop a unified framework for analyzing quantum mechanical resonances using the exact WKB method. The non-perturbative formulation based on the exact WKB method works for incorporating the Zel'dovich regularization, the complex scaling method, and the rigged Hilbert space. While previous studies have demonstrated the exact WKB analysis in bound state problems, our work extends its application to quasi-stationary states. By examining the inverted Rosen--Morse potential, we illustrate how the exact WKB analysis captures resonant phenomena in a rigorous manner. We explore the equivalence and complementarity of different well-established regularizations à la Zel'dovich and complex scaling within this framework. Also, we find the most essential regulator of functional analyticity and construct a modified Hilbert space of the exact WKB framework for resonance, which is called the rigged Hilbert space. This offers a deeper understanding of resonant states and their analytic structures. Our results provide a concrete demonstration of the non-perturbative accuracy of exact WKB methods in unstable quantum systems.
Comments:
19 pages, 6 figures, 1 table, to appear in JHEP
Subjects:
High Energy Physics — Theory (hep-th); Nuclear Theory (nucl-th); Quantum Physics (quant-ph)
arXiv:
2505.02301 [pdf]
JHEP(2025)·7 citations
18
[Submitted on 5 May 2025] (cross-list from hep-ph)
Local equilibrium Wigner function for spin-1/2 particles
Samapan Bhadury🇵🇱 · Zbigniew Drogosz🇵🇱 · Wojciech Florkowski🇵🇱 · Sudip Kumar Kar🇵🇱 · Valeriya Mykhaylova🇵🇱
Formal connections between the spin density matrix and the Wigner function for spin-1/2 particles forming a relativistic gas are explored to determine their general structures. They suggest that the commonly used form of the local equilibrium Wigner function should be replaced by a new expression. The latter fulfills the necessary condition for the normalization of the mean spin polarization, which the former fails to reproduce. The new definition of the Wigner function leads to generalized thermodynamic relations for perfect spin hydrodynamics, identical to those obtained earlier using the classical concept of spin. Moreover, one can prove that the perfect spin hydrodynamics based on the new equilibrium Wigner function is nonlinearly causal and stable. Finally, the selection rule for the Lagrange multipliers, which is satisfied by real systems, is discussed.
Comments:
Significantly revised version including discussion of the nonlinear causality and stability of spin hydrodynamics based on the new formula for the Wigner function
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2505.02657 [pdf]
13 citations

Affiliations

first authorsco-authorsvia INSPIRE

Connecting afterglow light curves to the GRB central engine

Realization of all-to-all fermion propagator for the first principle high accuracy strong interaction prediction

Chiral anomaly from (anomalous) spin hydrodynamics

Unified exact WKB framework for resonance -- Zel'dovich/complex-scaling regularization and rigged Hilbert space

Local equilibrium Wigner function for spin-1/2 particles

Affiliations