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Shu Luo

Publications and source records attributed to Shu Luo.

At least 19 recordsLinked to original sources

GiPL: Generative augmented iterative Pseudo-Labeling for Cross-Domain Few-Shot Object Detection

Vision-language foundation models have shown promising zero-shot generalization for Cross-Domain Few-Shot Object Detection (CD-FSOD). However, they face two critical challenges in fine-tuning: insufficient support set utilization due to sparse single-instance annotations, and severe overfitting under extremely limited target-domain samples. To address these issues, this paper proposes GiPL, an efficient two-branch training framework. In the first branch, we design an iterative pseudo-label self-training paradigm, which performs zero-shot inference on the support set to generate reliable pseudo-annotations, fuses them with ground-truth labels, and iteratively optimizes the model to fully exploit support set data. In the second branch, we introduce generative data augmentation pipeline using large vision-language models, which synthesizes domain-aligned, multi-object annotated images to enrich training samples and suppress overfitting. Extensive experiments on three challenging CD-FSOD datasets (RUOD, CARPK, CarDD) under 1/5/10-shot settings demonstrate that GiPL consistently outperforms state-of-the-art methods with significant performance gains. Code is available at \href{https://github.com/z-yaz/CDiscover}{CDiscover}.

cs.CV

The Second Challenge on Cross-Domain Few-Shot Object Detection at NTIRE 2026: Methods and Results

Cross-domain few-shot object detection (CD-FSOD) remains a challenging problem for existing object detectors and few-shot learning approaches, particularly when generalizing across distinct domains. As part of NTIRE 2026, we hosted the second CD-FSOD Challenge to systematically evaluate and promote progress in detecting objects in unseen target domains under limited annotation conditions. The challenge received strong community interest, with 128 registered participants and a total of 696 submissions. Among them, 31 teams actively participated, and 19 teams submitted valid final results. Participants explored a wide range of strategies, introducing innovative methods that push the performance frontier under both open-source and closed-source tracks. This report presents a detailed overview of the NTIRE 2026 CD-FSOD Challenge, including a summary of the submitted approaches and an analysis of the final results across all participating teams. Challenge Codes: https://github.com/ohMargin/NTIRE2026_CDFSOD.

cs.CV

Quantum-Corrected Evaporation and Absorption Cross-Section of Near-Extremal Rotating Black Holes

We revisit the Hawking evaporation history of low-temperature rotating black holes by taking into consideration the strong quantum fluctuations known to be present in the near-horizon, near-$\mathrm{AdS_2}$ throat region governed by an effective action that includes Schwarzian and two gauge modes. Imposing compatibility of this quantum framework with the semiclassical results creates a novel link of the black hole angular momentum and electric charge before and after emission, leading to a nontrivial interplay among the superradiance effect, eigenstate thermalization hypothesis and microscopic statistic description. We evaluate single scalar (neutral and charged) emission of Kerr-Newman and single and di-particle emission of photons, gravitons and spinors in the Kerr spacetime. We uncover that quantum corrections may affect late time evaporation rates, which further slows down the whole evaporation process because of the near-balance between the $s$-wave channel and the superradiance channel. Specifically, we find energy decay of the form $E(t)\sim t^{-8/21}$ for neutral scalar emission of a small, slowly rotating and charged black hole which differs from the analogous spherically symmetric quantum correction $E(t)\sim t^{-2/5}$ already suppressed with respect to the semiclassical rate $E(t)\sim t^{-1}$. We also discuss the quantum cross section for rotating black holes and point out various new features.

hep-th

Rescaled Leptonic Unitarity Triangles and Rephasing Invariants

The field of neutrino physics has made significant progress in measuring the strength and frequency of neutrino and antineutrino oscillations in the past two decades. It is clear that the amplitudes involved in the neutrino oscillation probabilities are all rephaping invariants of the quartet forms of the elements of the PMNS mixing matrix. We show in this paper how these quartet observables can be directly linked to the rescaled leptonic unitarity triangles within the framework of three active neutrinos. We provide a systematic discussion of the nine CP-conserving quartets ${\cal R}^{}_{\gamma k} \equiv {\rm Re} \left [ V^{}_{\alpha i} V^{}_{\beta j} V^{*}_{\alpha j} V^{*}_{\beta i}\right ] $ along with the universal Jarlskog invariant of CP violation ${\cal J} \equiv \sum_\gamma \epsilon^{}_{\alpha\beta\gamma} \sum_k \epsilon^{}_{ijk} \; {\rm Im} \left [ V^{}_{\alpha i} V^{}_{\beta j} V^{*}_{\alpha j} V^{*}_{\beta i} \right ]$, and place particular emphasis on the matter effect on these quartets. In addition to the well-known Naumov relation for the Jarlskog invariant ${\cal J}$, similar relations connecting ${\cal R}$ in vacuum and its effective counterparts $\widetilde{\cal R}$ in matter are introduced and examined in detail. We find that the effective CP-conserving invariants $\widetilde{\cal R}^{}_{\alpha i}$ in matter can be regarded as linear combinations of their vacuum counterparts. With the latest global fit data of neutrino masses and mixing elements, numerical analyses are carried out to give an intuitive understanding of how these rephasing invariants evolve as the matter density increases.

hep-ph

New rephasing invariants and CP violation built from the trios of the CKM or PMNS matrix elements

Given the $3\times 3$ Cabibbo-Kobayashi-Maskawa (CKM) quark flavor mixing matrix $V$, we define a new set of rephasing invariants in terms of the "trios" of its nine elements: $\lozenge^{ijk}_{\alpha\beta\gamma} \equiv (V^{}_{\alpha i} V^{}_{\beta j} V^{}_{\gamma k})/\det V$ with $\alpha \neq \beta \neq \gamma$ and $i \neq j \neq k$ running respectively over $(u, c, t)$ and $(d, s, b)$. We find that ${\rm Im} \lozenge^{ijk}_{\alpha\beta\gamma} = - {\cal J}$ holds, where ${\cal J}$ is the well-known Jarlskog invariant of weak CP violation. Analogous rephasing invariants $\blacklozenge^{ijk}_{\alpha\beta\gamma} \equiv (U^{}_{\alpha I} U^{}_{\beta j} U^{}_{\gamma k})/\det U$ can be defined for the $3\times 3$ Pontecorvo-Maki-Nakagawa-Sakata (PMNS) lepton flavor mixing matrix $U$, where $\alpha \neq \beta \neq \gamma$ and $i \neq j \neq k$ run respectively over $(e, \mu, \tau)$ and $(1, 2, 3)$. Taking into account small non-unitarity of $U$ based on the canonical seesaw mechanism for neutrino mass generation, we calculate ${\rm Im} \blacklozenge^{ijk}_{\alpha\beta\gamma}$ with the help of a full Euler-like block parametrization of the seesaw flavor structure and demonstrate that their leading terms converge to a universal invariant ${\cal J}^{}_\nu$ in the unitarity limit of $U$.

hep-ph

Thermodynamic law and holography dual of accelerating and rotating black hole in Nariai limit

In this study, we investigate the thermodynamic law of accelerating and rotating black hole described by ro- tating C-metric, as well as holography properties in Nariai limit, which are related to Nariai-CFT and Kerr-CFT correspondence. In order to achieve this goal we define a regularized Komar mass with physical interpretation of varying the horizon area from spinless limit to general case, and derive the frist law based on this construction through covariant phase space formalism. Serving for potential future studies, we also reduce the model to a 2-dimensional JT-type action and discuss some of its properties.

gr-qc

Black Hole Solutions with Electric and Magnetic Charges in Nonlinear Electrodynamic

This review article provides a comprehensive and self-contained overview of black hole solutions coupled to nonlinear electrodynamics (NLED) with both electric and magnetic charges. We systematically discuss the theoretical foundations, including the general action principle, the Hamiltonian P-framework for constructing exact solutions, and the classification of NLED theories (Born-Infeld, Euler-Heisenberg, power-law, logarithmic, exponential, and regular models). Detailed derivations are presented for dyonic black hole solutions in each theory, including explicit metric functions, asymptotic expansions, and horizon structures. The thermodynamic properties are examined in depth, including the first law, Smarr relations, heat capacities, extended phase space thermodynamics with p-V criticality, and the effect of magnetic charge on phase transitions. The geodesic structure is analyzed with complete calculations of null and timelike geodesics, photon spheres, black hole shadows, and gravitational lensing. Regular black hole solutions that resolve the central singularity are discussed with detailed analysis of energy conditions. Holographic applications via the AdS/CFT correspondence are explored, including holographic superconductors, entanglement entropy, and conductivity. Connections to quantum gravity through the weak gravity conjecture, swampland criteria, and string theory embeddings are examined.

gr-qc

The black hole shadow of quantum Oppenheimer-Snyder-de Sitter spacetime

In this study, we investigate the black hole shadow of an exact black hole solution of the loop quantum gravity (LQG) theory. We discuss some of its optical characteristics after generalizing it to the rotational case, including null geodesics and black hole shadow. From these we can compare the impact of different theories on the most deeply understood characteristics of the black hole and get a new way to test the accuracy of the modified gravity theory.

gr-qc

The quasinormal modes, pseudospectrum and time evolution of Proca fields in quantum Oppenheimer-Snyder-de Sitter spacetime

In this study, we investigate the quasinormal modes, pseudospectrum and time evolution of a massive vector field around a quantum corrected black hole in de-Sitter spacetime. We start by parameterization and using orthonormal tetrads to get the effective potential. Methodologically we use the hyperboloidal framework together with discretizing the non-selfadjoint operator through Chebyshev-Gauss-Labatto grid to attain the QNMs. We explore the parametric instability of QNMs caused by quantum correction, cosmological constant and Proca mass, and these three factors show very different influences on the QNMs' migration flow. On the other hand, we discuss the instability of QNMs with arbitrary-shape perturbation and the effectiveness of numerical results through pseudospectrum. We use high frequency approximation to attain the expression of the time domain Green function and clarify the origin of two different stages in time evolution. Through numerical methods we confirm that no power-law late time tail is expected, and the possible impact on time evolution caused by quantum correction is discussed.

gr-qc

First determination of the Jarlskog invariant of CP violation from the moduli of the CKM matrix elements

We find that the precision and accuracy of current experimental data on the moduli of nine Cabibbo-Kobayashi-Maskawa (CKM) quark flavor mixing matrix elements allow us to numerically determine the it correct size of the Jarlskog invariant of CP violation from four of them in eight different ways for the first time without making any special assumptions. This observation implies a remarkable self-consistency of the correlation between CP-conserving and CP-violating quantities of the CKM matrix as guaranteed by its unitarity.

hep-ph

A Pythagoras-like theorem for CP violation in neutrino oscillations

The probabilities of $\nu^{}_{\mu} \to \nu^{}_{e}$ and $\overline{\nu}^{}_{\mu} \to \overline{\nu}^{}_{e}$ oscillations in vacuum are determined by the CP-conserving flavor mixing factors ${\cal R}^{}_{ij} \equiv {\rm Re} (U^{}_{\mu i} U^{}_{e j} U^{*}_{\mu j} U^{*}_{e i})$ and the universal Jarlskog invariant of CP violation ${\cal J}^{}_{\nu} \equiv (-1)^{i+j} \; {\rm Im} (U^{}_{\mu i} U^{}_{e j} U^{*}_{\mu j} U^{*}_{e i})$ (for $i, j = 1, 2, 3$ and $i < j$), where $U$ is the $3\times 3$ Pontecorvo-Maki-Nakagawa-Sakata neutrino mixing matrix. We show that ${\cal J}^{2}_{\nu} = {\cal R}^{}_{12} {\cal R}^{}_{13} + {\cal R}^{}_{12} {\cal R}^{}_{23} + {\cal R}^{}_{13} {\cal R}^{}_{23}$ holds as a natural consequence of the unitarity of $U$. This Pythagoras-like relation may provide a novel cross-check of the result of ${\cal J}^{}_{\nu}$ that will be directly measured in the next-generation long-baseline neutrino oscillation experiments. Indirect non-unitarity effects and terrestrial matter effects on ${\cal J}^{}_{\nu}$ and ${\cal R}^{}_{ij}$ are also discussed.

hep-ph

Hybrid Weyl-type bound for $p$-power twisted $\mathrm{GL} (2)$ $L$-functions

Let $g$ be a fixed holomorphic cusp form of arbitrary level and nebentypus. Let $\chi$ be a primitive character of prime-power modulus $q = p^{\gamma}$. In this paper, we prove the following hybrid Weyl-type subconvexity bound \begin{align*} L (1/2 + it, g \otimes \chi) \ll_{g, p, \varepsilon} ( (1+|t|) q )^{1/3+ \varepsilon} \end{align*} for any $\varepsilon > 0$.

math.NT

Neutrino Oscillation in Dense Matter

As the increasing of neutrino energy or matter density, the neutrino oscillation in matter may undergo "vacuum-dominated", "resonance" and "matter-dominated" three different stages successively. Neutrinos endure very different matter effects, and therefore present very different oscillation behaviors in these three different cases. In this paper, we focus on the less discussed matter-dominated case (i.e., $|A^{}_{\rm CC}| \gg |\Delta m^{2}_{31}|$), study the effective neutrino mass and mixing parameters as well as neutrino oscillation probabilities in dense matter using the perturbation theory. We find that as the matter parameter $|A^{}_{\rm CC}|$ growing larger, the effective mixing matrix in matter $\tilde{V}$ evolves approaching a fixed $3 \times 3$ constant real matrix which is free of CP violation and can be described using only one simple mixing angle $\tilde{\theta}$ which is independent of $A^{}_{\rm CC}$. As for the neutrino oscillation behavior, $\nu^{}_{e}$ decoupled in the matter-dominated case due to its intense charged-current interaction with electrons while a two-flavor oscillation are still presented between $\nu^{}_{\mu}$ and $\nu^{}_{\tau}$. Numerical analysis are carried on to help understanding the salient features of neutrino oscillation in matter as well as testing the validity of those concise approximate formulas we obtained. At the end of this paper, we make a very bold comparison of the oscillation behaviors between neutrinos passing through the Earth and passing through a typical white dwarf to give some embryo thoughts on under what circumstances these studies will be applied and put forward the interesting idea of possible "neutrino lensing" effect.

hep-ph

Neutrino Oscillation Probabilities in Matter with Direct and Indirect Unitarity Violation in the Lepton Mixing Matrix

In the presence of both direct and indirect unitarity violation in the lepton mixing matrix, we derive a complete set of series expansion formulas for neutrino oscillation probabilities in matter of constant density. Expansions in the mass hierarchy parameter $α\equiv Δm_{21}^{2} / Δm_{31}^{2}$ and those unitarity violation parameters $s^{2}_{ij}$ (for i = 1, 2, 3 and j = 4, 5, 6) up to the first order are studied in this paper. We analyse the accuracy of the analytical series expansion formulas in different regions of L / E. A detailed numerical analysis is also performed, of which the different effects of the direct and the indirect unitarity violation are particularly emphasized. We also study in this paper the summed $ν^{}_α \rightarrow ν^{}_{e, ν, τ}$ probabilities, whose deviation from the unity provides a definite signal of the unitarity violation.

hep-ph

Search for Sub-eV Sterile Neutrinos in the Precision Multiple Baselines Reactor Antineutrino Oscillation Experiments

According to different effects on neutrino oscillations, the unitarity violation in the MNSP matrix can be classified into the direct unitarity violation and the indirect unitarity violation which are induced by the existence of the light and the heavy sterile neutrinos respectively. Of which sub-eV sterile neutrinos are of most interesting. We study in this paper the possibility of searching for sub-eV sterile neutrinos in the precision reactor antineutrino oscillation experiments with three different baselines at around 500 m, 2 km and 60 km. We find that the antineutrino survival probabilities obtained in the reactor experiments are sensitive only to the direct unitarity violation and offer very concentrated sensitivity to the two parameters $θ^{}_{14}$ and $Δm^{2}_{41}$. If such light sterile neutrinos do exist, the active-sterile mixing angle $θ^{}_{14}$ could be acquired by the combined rate analysis at all the three baselines and the mass-squared difference $Δm^{2}_{41}$ could be obtained by taking the Fourier transformation to the L / E spectrum. Of course, for such measurements to succeed, both high energy resolution and large statistics are essentially important.

hep-ph

Resolving the octant of theta_{23} via radiative mu-tau symmetry breaking

We point out that the observed neutrino mixing pattern at low energies is very likely to originate from the 3 times 3 lepton flavor mixing matrix U which possesses the exact mu-tau permutation symmetry |U_{mu i}| = |U_{tau i}| (for i=1,2,3) at a superhigh energy scale Lambda_{mu tau} \sim 10^{14} GeV. The deviation of theta_{23} from 45^\circ and that of delta from 270^\circ in the standard parametrization of U are therefore a natural consequence of small mu-tau symmetry breaking via the renormalization-group equations (RGEs) running from Lambda_{mu tau} down to the electroweak scale Lambda_{EW} \sim 10^2 GeV. In fitting current experimental data we find that the RGE-corrected value of theta_{23} is uniquely correlated with the neutrino mass ordering: theta_{23} \simeq 42.4^\circ reported by Capozzi et al (or theta_{23} \simeq 48.9^\circ reported by Forero et al) at Lambda_{EW} can arise from theta_{23} = 45^\circ at Lambda_{mu tau} in the minimal supersymmetric standard model if the neutrino mass ordering is inverted (or normal). Accordingly, the preliminary best-fit results of delta at Lambda_{EW} can also evolve from delta = 270^\circ at Lambda_{mu tau} no matter whether the massive neutrinos are Dirac or Majorana particles.

hep-ph

Global Neutrino Heating in Hyperaccretion Flows

The neutrino-dominated accretion flow (NDAF) with accretion rates \dot{M} = 0.01 - 10 M_{\sun} s^{-1} is a plausible candidate for the central engine of gamma-ray bursts (GRBs). This hyperaccretion disk is optically thin to neutrinos in the radial direction, therefore the neutrinos produced at one radius can travel for a long distance in the disk. Those neutrinos can thus be absorbed with certain probability by the disk matter at the other radius and heat the disk there. The effect of this "global neutrino heating" has been ignored in previous works and is the focus of this paper. We find that around the "ignition" radius r_{ign}, the global neutrino heating rate could be comparable to or even larger than the local viscous heating rate thus must be an important process. Two possible consequences are in order if the "global neutrino heating" is taken into account: i) the temperature of the disk is slightly raised and the "ignition" radius r_{ign} slightly shifts to a larger radius, both lead to the increasing of the total neutrino flux; ii) what is more interesting is that, the temperature of the ADAF just beyond r_{ign} may be raised above the virial temperature thus the accretion will be suppressed. In this case, the activity of the black hole is expected to oscillate between an active and inactive phases. The timescale of the active phases is estimated to be \sim 1 second. If the timescale of the inactive phase is comparable to or less than this value, this intermittent activity may explain the slow variability component of the GRBs. Self-consistent global calculations of NDAFs with the "global neutrino heating" included are required in the future to more precisely evaluate this effect.

astro-ph.HE

Theoretical Overview on the Flavor Issues of Massive Neutrinos

We present an overview on some basic properties of massive neutrinos and focus on their flavor issues, including the mass spectrum, flavor mixing pattern and CP violation. The lepton flavor structures are explored by taking account of the observed value of the smallest neutrino mixing angle θ_{13}. The impact of θ_{13} on the running behaviors of other flavor mixing parameters is discussed in some detail. The seesaw-induced enhancement of the electromagnetic dipole moments for three Majorana neutrinos is also discussed in a TeV seesaw scenario.

hep-ph