标题： 关于可能的偏振效应对光传播的影响 显示英文标题

标题： On possible skewon effects on light propagation

摘要： 我们从电磁激发与场强之间的局部线性时空关系开始。然后研究光子路径和光波的一般协变菲涅耳曲面。时空的度规和联络未被指定。因此，我们的框架非常适合于寻找可能违反洛伦兹对称性的扩展标准模型光子部分的可能性。我们讨论了构成张量的偏斜部分（如果适当参数化）如何影响菲涅耳曲面并干扰真空电动力学的光锥。指定了条件，使原始四次菲涅耳曲面减少为双光锥结构（双折射）和单光锥。定性地说，实偏斜场的效果可以与吸收性介质中的效果相比。相反，虚偏斜场可以用非吸收性介质中的自然旋光性和法拉第效应来解释。伽马射线暴的天体物理数据被用来推导偏斜场大小的上限。 显示英文摘要

摘要： We start from a local and linear spacetime relation between the electromagnetic excitation and the field strength. Then we study the generally covariant Fresnel surfaces for light rays and light waves. The metric and the connection of spacetime are left unspecified. Accordingly, our framework is ideally suited for a search of possible violations of the Lorentz symmetry in the photon sector of the extended standard model. We discuss how the skewon part of the constitutive tensor, if suitably parametrized, influences the Fresnel surfaces and disturbs the light cones of vacuum electrodynamics. Conditions are specified that yield the reduction of the original quartic Fresnel surface to the double light cone structure (birefringence) and to the single light cone. Qualitatively, the effects of the real skewon field can be compared to those in absorbing material media. In contrast, the imaginary skewon field can be interpreted in terms of non-absorbing media with natural optical activity and Faraday effects. The astrophysical data on gamma-ray bursts are used for deriving an upper limit for the magnitude of the skewon field.