Gauge field and fermion production during axion inflation
Gauge field and fermion production during axion inflation
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轴子膨胀期间的规范场和费米子产生
DOI：
10.1088/1475-7516/2018/11/020
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发表时间：
2018
影响因子：
6.4
通讯作者：
K. Mukaida
中科院分区：
文献类型：
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作者：
V. Domcke;K. Mukaida
本文研究了在手征反常存在下，通过与赝标暴胀子的Chern-Simons（CS）耦合，螺旋阿贝尔规范场和手征费米子的双重产生。通过CS项，暴胀子的运动导致规范场两个螺旋度之一的快子不稳定性。我们表明，由此产生的螺旋规范场必然导致生产手征费米子变形到离散的朗道能级的费米球。最低的朗道水平的人口导致手性的不对称性，从手性异常推断，而较高的水平是通过对生产对称填充。从规范场产生的费米子的反作用，我们得到一个保守的，但严格的上限的规范场的大小。因此，我们发现这些螺旋规范场引起的标量扰动（导致小尺度上增强的结构形成）显着减少。我们还讨论了原始手征不对称性和膨胀后的螺旋规范场的命运，并表明手征等离子体中的不稳定性往往会消除这些原始的不对称性。这一结果可能会影响宇宙的重子不对称性与原始磁场有关的场景。
We study the dual production of helical Abelian gauge fields and chiral fermions through the Chern-Simons (CS) coupling with a pseudo-scalar inflaton in the presence of a chiral anomaly. Through the CS term, the motion of the inflaton induces a tachyonic instability for one of the two helicities of the gauge field. We show that the resulting helical gauge field necessarily leads to the production of chiral fermions by deforming their Fermi sphere into discrete Landau levels. The population of the lowest Landau level leads to a chiral asymmetry as inferred from the chiral anomaly, while the higher levels are populated symmetrically through pair production. From the backreaction of the fermions on the gauge field production we derive a conservative but stringent upper bound on the magnitude of the gauge fields. Consequently, we find that the scalar perturbations sourced by these helical gauge fields, responsible for enhanced structure formation on small scales, get reduced significantly. We also discuss the fate of the primordial chiral asymmetry and of the helical gauge fields after inflation, and show that the instability in the chiral plasma tends to erase these primordial asymmetries. This result may impact scenarios where the baryon asymmetry of the Universe is connected to primordial magnetic fields.
DOI：
10.1088/1475-7516/2016/12/026
发表时间：
2016-12-01
影响因子：
6.4
作者：
Bartolo, Nicola;Caprini, Chiara;Tasinato, Gianmassimo
通讯作者：
Tasinato, Gianmassimo