通过伸缩子场中介增强引力 - 电磁耦合:从超辐射云到脉冲星 TOA 相位调制(Enhanced Gravito-Electromagnetic Coupling via Dilaton Field Mediation: From Superradiance Clouds to Pulsar TOA Phase Modulation)

中文摘要我们提出 “中间场桥接” 策略:引入伸缩子场(φ)作为主动型中间媒介,在引力与电磁已有几何耦合之外建立一条由非线性耦合 βφ²F² 支配的并行新通道。在旋转黑洞环境中,超轻伸缩子场通过超辐射不稳定性形成非轴对称的超辐射云。云以本征角速度绕黑洞转动,对穿过其中的毫秒脉冲星信号产生周期性光程延迟调制。本工作聚焦于超大质量黑洞(如银河系中心 Sgr A*,M~4×10⁶ M☉)与超轻伸缩子(μ~10⁻¹⁸ eV)的参数组合,预期调制频率落在亚 μHz 波段(周期约 5 天),TOA 调制幅度约 3 纳秒,接近 FAST 经长期积分后的测量精度极限。该效应的核心识别判据是其与观测频率无关的特性,可通过双频段同步观测(如 FAST 400 MHz 与 1400 MHz)与等离子体色散效应明确区分。本框架表明:在极端天体物理环境中,被微扰论丢弃的微小项可成为通往新物理的入口,为探测超轻伸缩子场和检验超出标准模型的新物理提供了可行的观测途径。AbstractWe propose an "intermediate-field bridging" strategy: we introduce the dilaton field (φ) as an active intermediate mediator to establish a new parallel channel governed by the nonlinear coupling term βφ²F², beyond the existing geometric coupling between gravitation and electromagnetism. Around a rotating black hole, the ultralight dilaton field forms a non-axisymmetric superradiance cloud via the superradiant instability. The cloud rotates around the black hole at its eigen-angular velocity and imposes a periodic optical path delay modulation on millisecond pulsar signals passing through it.This work focuses on the parameter combination of a supermassive black hole (e.g., Sgr A* at the Galactic center, M ~ 4×10⁶ M☉) and an ultralight dilaton (μ ~ 10⁻¹⁸ eV). The expected modulation frequency falls in the sub-μHz band (period ~ 5 days), with a TOA modulation amplitude of approximately 3 nanoseconds — close to the measurement precision limit of the Five-hundred-meter Aperture Spherical radio Telescope (FAST) after long-term integration. The core identification criterion of this effect is its independence from observation frequency, which can be clearly distinguished from plasma dispersion effects via simultaneous dual-band observations (e.g., FAST at 400 MHz and 1400 MHz).This framework demonstrates that in extreme astrophysical environments, tiny terms discarded by perturbation theory can serve as gateways to new physics, providing a feasible observational approach for detecting ultralight dilaton fields and testing new physics beyond the Standard Model.