Dark Matter and Torsion

由 Barbero-Immirzi 参数约束的挠率质量介导的轴子–光子混合暗物质转换

Axion-photon-mixing dark matter conversion mediated by torsion mass constrained by the Barbero-Immirzi parameter

本文在 Einstein-Cartan-Holst 框架下研究挠率介导的光子–轴子–暗光子混合，导出 BI 参数对挠率与暗轴子质量的严格约束。

Dark energy fifth forces in torsion pendulum experiments

The chameleon scalar field is a matter-coupled dark energy candidate whose nonlinear self-interaction partially screens its fifth force at laboratory scales. Nevertheless, small-scale experiments such as the torsion pendulum can provide powerful constraints on chameleon models. Here we develop a simple approximation for computing chameleon fifth forces in torsion pendulum experiments such as Eot-Wash. We show that our approximation agrees well with published constraints on the quartic chameleon, and we use it to extend these constraints to a much wider range of models. Finally, we forecast the…

扭力平衡实验可直接探测亚电子暗物质

Torsion Balance Experiments Enable Direct Detection of Sub-eV Dark Matter

研究通过扭力平衡实验探测亚电子暗物质，利用相干效应增强散射截面，现有实验对暗物质-核子散射的约束最为严格。

由Barbero-Immirzi参数和轴子-挠率嬗变诱导的暗光子与快子不稳定性

Dark photons and tachyonic instability induced by Barbero-Immirzi parameter and axion-torsion transmutation

本文通过最小和非最小耦合挠率研究Holst引力，将约束常数系数技术扩展至暗光子研究，推导出约0.775的BI参数，并探讨暗光子磁螺旋度不稳定性与轴子振荡频率对BI参数的依赖。

Neutrinos in the Early Universe, Kalb-Ramond Torsion and Matter-Antimatter Asymmetry

The generation of a matter-antimatter asymmetry in the Universe may be induced by the propagation of fermions in non-trivial, spherically asymmetric (and hence Lorentz violating) gravitational backgrounds. Such backgrounds may characterise the epoch of the early universe. The key point in these models is that the background induces different dispersion relations, hence populations, between fermions and antifermions, and thus CPT Violation (CPTV) appears in thermal equilibrium. Species populations may freeze out leading to leptogenesis and baryogenesis. We consider here a string-inspired scenar…

Probing dark gauge boson via Einstein-Cartan portal

Einstein-Cartan gravity which is an alternative formulation of general relativity introduces new degrees of freedom contained in the torsion field which encodes the torsion feature of spacetime. Interestingly, the torsion field couples to all fermions through its axial-vector mode with a universal coupling $η=1/8$ which is possible to change under the quantum effects. We argue that Einstein-Cartan gravity provides a significant portal to probe $A'$ dark gauge boson which resides in dark sector existing as an invisible world parallel to our own and couples to the standard model (SM) particles t…

A First Experimental Limit on In-matter Torsion from Neutron Spin Rotation in Liquid He-4

We report the first experimental upper bound to our knowledge on possible in-matter torsion interactions of the neutron from a recent search for parity violation in neutron spin rotation in liquid He-4. Our experiment constrains a coefficient $ζ$ consisting of a linear combination of parameters involving the time components of the torsion fields $T^μ$ and $A^μ$ from the nucleons and electrons in helium which violates parity. We report an upper bound of $|ζ|<9.1x10^{-23}$ GeV at 68% confidence level and indicate other physical processes that could be analyzed to constrain in-matter torsion.

Einstein-Cartan Gravity with Torsion Field Serving as Origin for Cosmological Constant or Dark Energy Density

We analyse the Einstein-Cartan gravity in its standard form cal-R = R + cal-K^2, where cal-R and R are the Ricci scalar curvatures in the Einstein-Cartan and Einstein gravity, respectively, and cal-K^2 is the quadratic contribution of torsion in terms of the contorsion tensor cal-K. We treat torsion as an external (or a background) field and show that the contribution of torsion to the Einstein equations can be interpreted in terms of the torsion energy-momentum tensor, local conservation of which in a curved spacetime with an arbitrary metric or an arbitrary gravitational field demands a prop…

用于直接探测超轻矢量暗物质的差分扭力传感器

Differential torsion sensor for direct detection of ultralight vector dark matter

提出一种双扭摆差分传感器，用于直接探测超轻矢量暗物质，在10^-2-10 Hz频段实现增强差分扭矩灵敏度，预计对耦合常数的约束可达10^-27量级。

极化物质中中子自旋旋转对挠率与非度量性的约束

Torsion and Nonmetricity Constraints From Neutron Spin Rotation in Polarized Matter

本研究应用有效场论方法表征粒子算符与时空挠率、非度量性的耦合，利用补偿铁氧体的中子自旋旋转数据，首次对相关物质内组合施加约束。

Superconducting Cosmic String with Propagating Torsion

We show that it is possible to construct a consistent model describing a current-carrying cosmic string endowed with torsion. The torsion contribution to the gravitational force and geodesics of a test-particle moving around the SCCS are analyzed. In particular, we point out two interesting astrophysical phenomena in which the higher magnitude force we derived may play a critical role: the dynamics of compact objects orbiting the torsioned SCCS and accretion of matter onto it. The deficit angle associated to the SCCS can be obtained and compared with data from the Cosmic Background Explorer (C…

探索长基线实验中手征挠率对中微子振荡的影响

Exploring the Effect of Chiral Torsion on Neutrino Oscillation in Long Baseline Experiments

本文研究弯曲时空中挠率诱导的四费米子相互作用对长基线中微子振荡的影响，并利用 DUNE 限制挠率耦合参数、评估其物理灵敏度。

用悬浮铁磁扭转振荡器搜索超轻轴子暗物质

Search for Ultralight Axion Dark Matter with a Levitated Ferromagnetic Torsional Oscillator

利用悬浮铁磁扭转振荡器探测超轻轴子暗物质，通过高真空和磁屏蔽获得18000秒数据，设定90%置信度限，未来计划通过优化提升灵敏度。

Neutrino oscillation in a space-time with torsion

Using the Einstein-Cartan-Dirac theory, we study the effect of torsion on neutrino oscillation. We see that torsion cannot induce neutrino oscillation, but affects it whenever oscillation exists for other reasons. We show that the torsion effect on neutrino oscillation is as important as the neutrino mass effect, whenever the ratio of neutrino number density to neutrino energy is $\sim 10^{69}$ cm$^{-3}$ /eV, or the number density of the matter is $\sim 10^{69}$ cm$^{-3}$.

暗物质混合中子星的壳层：整体性质与扭振振荡

The crust of dark-matter admixed neutron stars: bulk properties and torsional oscillations

研究暗物质对中子星壳层厚度及扭振振荡谱的影响，发现暗物质分布位于星体内部时壳层变薄，振荡频率升高，并探讨了与电子屏蔽效应的简并性。

Consequences of Propagating Torsion in Connection-Dynamic Theories of Gravity

We discuss the possibility of constraining theories of gravity in which the connection is a fundamental variable by searching for observational consequences of the torsion degrees of freedom. In a wide class of models, the only modes of the torsion tensor which interact with matter are either a massive scalar or a massive spin-1 boson. Focusing on the scalar version, we study constraints on the two-dimensional parameter space characterizing the theory. For reasonable choices of these parameters the torsion decays quickly into matter fields, and no long-range fields are generated which could be…

宇宙中是否存在由量子修正、Nieh-Yan引力和Barbero-Immirzi场诱导的手征暗磁发电机？

Is there a chiral dark dynamo in the universe induced by quantum correction, Nieh-Yan gravity and Barbero-Immirzi field?

本文在Einstein-Cartan-Holst框架下引入挠率质量和量子修正，研究Immirzi场驱动的宇宙暗磁发电机，解析求解早期与晚期宇宙磁场演化，并给出QCD相变期及当前宇宙的磁场强度估计。

在√s = 13.6 TeV质子-质子碰撞模拟中，基于爱因斯坦-嘉当门户框架搜索暗规范玻色子的产生

Search for the production of dark gauge bosons in the framework of Einstein-Cartan portal in the simulation of proton-proton collisions at $\sqrt{s} = 13.6$ TeV

本研究在LHC 13.6 TeV质心能量、52 fb⁻¹积分亮度下模拟质子-质子碰撞，搜索爱因斯坦-嘉当门户框架中暗规范玻色子相关的重挠场产生，分析双μ子加横向缺失能量事件并给出相关粒子质量上限。

用扭力平衡测试非经典物质的弱等效原理

Testing the weak equivalence principle for nonclassical matter with torsion balances

本文提出利用扭力平衡测试弱等效原理，通过量子相干态的叠加和测量角加速度来检测可能的WEP违反。

Einstein-Cartan引力中由挠率诱导的物质流与scalaron耦合

Torsion induced current-scalaron coupling in Einstein-Cartan gravity

本文研究了Einstein-Cartan引力中挠率诱导的物质流与scalaron耦合，展示了通用结果和具体例子，为暴胀后重加热、重子生成及QCD θ项研究提供了理论基础。

Dark sector unifications: dark matter-phantom energy, dark matter -- constant $w$ dark energy, dark matter-dark energy-dark matter

The paper brings a novel approach to unification of dark matter and dark energy in terms of a cosmic fluid. A model is introduced in which the cosmic fluid speed of sound squared is defined as a function of its equation of state (EoS) parameter. It is shown how logarithmic part of this function results in dynamical regimes previously not observed in cosmic fluid models. It is shown that in a particular dynamical regime the model behaves as a unification of dark matter and phantom dark energy. Further, it is shown that the model may describe dark matter - dark energy unification in which dark e…