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arXiv 1606.08474astro-ph.CO
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轴子暴胀的磁成因

Magnetogenesis from axion inflation

Peter Adshead, John T. Giblin, Timothy R. Scully, Evangelos I. Sfakianakis

摘要:

在这项工作中,我们计算的生产磁场模型的轴子膨胀耦合到超荷部门的标准模型通过陈-西蒙斯相互作用项。我们选择了最简单的二次暴胀势,并利用晶格模拟计算了暴胀结束时的磁场强度、螺旋度和相关长度。对于小的轴子-规范场耦合强度的值,结果与文献中发现的无反作用计算和估计一致。对于较大的耦合的螺旋度的磁场不同,从无反作用的估计,并强烈依赖于共动波数。我们估计后膨胀的演变的磁场的螺旋和非螺旋磁场的演变的基础上的已知结果。与$U(1)_Y$有大耦合的轴子暴胀产生的磁场可以达到$B_{\rm eff} \gtrsim 10^{-16}\, {\rm G}$,表现出场强$B_{\rm phys} \approx 10^{-13}\, {\rm G}$和相关长度$λ_{\rm phys}\approx10\, {\rm pc}$。这个结果对耦合的精确值不敏感,只要耦合足够大以允许瞬时预热。根据对决定耀变体性质的物理过程的假设,可以发现这些场与基于$B_{\rm eff}$值的耀变体观测结果一致。最后,大耦合的磁场强度足以满足最近提出的重子生成机制的要求,该机制利用了标准模型的手征异常。

英文摘要:

In this work we compute the production of magnetic fields in models of axion inflation coupled to the hypercharge sector of the Standard Model through a Chern-Simons interaction term. We make the simplest choice of a quadratic inflationary potential and use lattice simulations to calculate the magnetic field strength, helicity and correlation length at the end of inflation. For small values of the axion-gauge field coupling strength the results agree with no-backreaction calculations and estimates found in the literature. For larger couplings the helicity of the magnetic field differs from the no-backreaction estimate and depends strongly on the comoving wavenumber. We estimate the post-inflationary evolution of the magnetic field based on known results for the evolution of helical and non-helical magnetic fields. The magnetic fields produced by axion inflation with large couplings to $U(1)_Y$ can reach $B_{\rm eff} \gtrsim 10^{-16}\, {\rm G}$, exhibiting a field strength $B_{\rm phys} \approx 10^{-13}\, {\rm G}$ and a correlation length $λ_{\rm phys}\approx10\, {\rm pc}$. This result is insensitive to the exact value of the coupling, as long as the coupling is large enough to allow for instantaneous preheating. Depending on the assumptions for the physical processes that determine blazar properties, these fields can be found consistent with blazar observations based on the value of $B_{\rm eff}$. Finally, the intensity of the magnetic field for large coupling can be enough to satisfy the requirements for a recently proposed baryogenesis mechanism, which utilizes the chiral anomaly of the Standard Model.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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