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量子论坛:Constraining Scalar-Photon Couplings with Cosmological Observations

发布人:日期:2017-01-17浏览数:

量子论坛第二讲:

报告题目:Constraining Scalar-Photon Couplings with Cosmological Observations

报告人:Anastasios Avgoustidis

报告时间:2017年1月8日 16:00

报告地点:量子楼410报告厅

报告人简介:2003-2006: PhD in Theoretical Cosmology, University of Cambridge, UK;

2006–2008: Marie-Curie RTN Postdoctoral Position, University of Barcelona, Spain;

2009–2011: CTC Research Fellow, University of Cambridge, UK;

2011–2013: Marie-Curie Research Fellow, University of Nottingham, UK;

2013–present: Nottingham Advanced Research Fellow, University of Nottingham, UK.

报告摘要:Scalar and pseudoscalar fields are generically present in fundamental theories of the early universe. Axions, for example, provide an elegant solution to the strong CP problem, while other axion-like (pseudo)scalars arise naturally in theories with extra dimensions. Such fields have couplings to the electromagnetic sector, providing an exciting opportunity to constrain high-energy physics using astrophysical photons in the observable universe. In particular, scalar-photon couplings induce deviations from the standard distance-duality relation and I will discuss how distance determinations in cosmology can be used to obtain strong constraints on axion-like particles. Similar techniques also apply to other scalar fields like those invoked in evolving Dark Energy models. For such cases, I will point out additional effects on the CMB temperature evolution T(z), which are parametrically related to distance-duality deviations and can thus be used to break degeneracies in Dark Energy parameter estimations. I will also present the latest constraints on T(z) and discuss their implications.