Axion Like Particles (ALPs) are predicted to couple with photons in the presence of magnetic fields. This effect may lead to a significant change in the observed spectra of gamma-ray sources such as AGNs. Here we carry out a detailed study that for the first time simultaneously considers in the same framework both the photon/axion mixing that takes place in the gamma-ray source and that one expected to occur in the intergalactic magnetic fields. An efficient photon/axion mixing in the source always means an attenuation in the photon flux, whereas the mixing in the intergalactic medium may result in a decrement and/or enhancement of the photon flux, depending on the distance of the source and the energy considered. Interestingly, we find that decreasing the value of the intergalactic magnetic field strength, which decreases the probability for photon/axion mixing, could result in an increase of the expected photon flux at Earth if the source is far enough. We also find a 30% attenuation in the intensity spectrum of distant sources, which occurs at an energy that only depends on the properties of the ALPs and the intensity of the intergalactic magnetic field, and thus independent of the AGN source being observed. Moreover, we show that this mechanism can easily explain recent puzzles in the spectra of distant gamma-ray sources... [ABRIDGED] The consequences that come from this work are testable with the current generation of gamma-ray instruments, namely Fermi (formerly known as GLAST) and imaging atmospheric Cherenkov telescopes like CANGAROO, HESS, MAGIC and VERITAS.
Comment on "Irregularity in gamma ray source spectra as a signature of axion-like particles"
D. Wouters和P.Brun在Phys.Rev.D86，043005（2012）中声称，在遥远的甚高能量耀变体的光谱中的可观察效应是由于在湍流的河外磁场存在下光子振荡成类轴子粒子（ALP）的结果。本评论的主要目的是证明这样的结果在物理上是不正确的。我们还表明，物理上正确的处理同一问题导致一个不太相关的结论，这使得WB指出的效果可能无法观察到与目前的能力。
New constraints on axion with gamma-ray observations of the Crab Nebula
National Astronomical Observatory of Japan (NAOJ)（日本国立天文台）；Graduate University for Advanced Studies (SOKENDAI)（高级研究院）；High Energy Accelerator Research Organization (KEK)（高能加速器研究机构）；The University of Tokyo（东京大学）
Large lepton asymmetry from axion inflation and helium abundance hinted by ACT
School of Fundamental Physics and Mathematical Sciences, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences (HIAS-UCAS)（中国科学院大学前沿科学与高等研究院基础物理与数学学院）；Institute of Theoretical Physics, Chinese Academy of Sciences（中国科学院理论物理研究所）；University of Chinese Academy of Sciences（中国科学院大学）；International Centre for Theoretical Physics Asia-Pacific (ICTP-AP)（亚太理论物理中心）；Research Center for the Early Universe, The University of Tokyo（东京大学早期宇宙研究中心）
Reappraisal of the Constraints on Heavy Axion-like Particles from Gamma-Ray Bursts
Washington University（华盛顿大学）；Johannes Gutenberg-Universität Mainz（美因茨约翰内斯古腾堡大学）；SISSA, International School for Advanced Studies（国际高等研究学院）；IFPU, Institute for Fundamental Physics of the Universe（宇宙基础物理研究所）；INFN, Sezione di Trieste（意大利国家核物理研究所的里雅斯特分部）；University of Johannesburg（约翰内斯堡大学）；The George Washington University（乔治华盛顿大学）
我们研究了带电粒子在空间常数但随时间变化的赝标背景中的传播。物理上，这种赝标量背景可以由残余轴子密度提供。背景导致洛伦兹不变性的明显破坏;因此，p-> p γ的过程是可能的，背景充当了对极高能宇宙射线的屏蔽，这种效应有点类似于GZK截止效应。该效应与模型无关，可以精确计算。假设探测到通过这种机制辐射的光子，将提供一种间接的方式来验证轴子的宇宙学相关性。
Solar axion searches with RES-NOVA: projected sensitivity and first prototype limit
Laboratorio Energia Nucleare Applicata（应用核能实验室）；INFN Sezione di Pavia（意大利国家核物理研究所帕维亚分部）；Gran Sasso Science Institute（格兰萨索科学研究所）；INFN Laboratori Nazionali del Gran Sasso（意大利国家核物理研究所格兰萨索国家实验室）；Dipartimento di Fisica, Università di Milano - Bicocca（米兰比可卡大学物理系）；INFN Sezione di Milano - Bicocca（意大利国家核物理研究所米兰比可卡分部）；Shanghai Institute of Ceramics, CAS（中国科学院上海陶瓷研究所）
