The Experiment to Detect the Global Epoch of Reionisation Signature (EDGES) collaboration has recently reported an important result related to the absorption signal in the Cosmic Microwave Background radiation spectrum. This signal corresponds to the red-shifted 21-cm line at z similar or equal to 17.2, whose amplitude is about twice the expected value. This represents a deviation of approximately 3.8 sigma from the predictions of the standard model of cosmology, i.e. the ACDM model. This opens a window for testing new physics beyond both the standard model of particle physics and the ACDM model. In this work, we explore the possibility of explaining the EDGES anomaly in terms of modified dispersion relations. The latter are typically induced in unified theories and theories of quantum gravity, such as String/M-theories and Loop Quantum Gravity. These modified dispersion relations affect the density of states per unit volume and thus the thermal spectrum of the Cosmic Microwave Background photons. The temperature of the 21-cm brightness temperature is modified accordingly giving a potential explanation of the EDGES anomaly.
Modified dispersion relations and a potential explanation of the EDGES anomaly
Lambiase, GaetanoMembro del Collaboration Group
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2022-01-01
Abstract
The Experiment to Detect the Global Epoch of Reionisation Signature (EDGES) collaboration has recently reported an important result related to the absorption signal in the Cosmic Microwave Background radiation spectrum. This signal corresponds to the red-shifted 21-cm line at z similar or equal to 17.2, whose amplitude is about twice the expected value. This represents a deviation of approximately 3.8 sigma from the predictions of the standard model of cosmology, i.e. the ACDM model. This opens a window for testing new physics beyond both the standard model of particle physics and the ACDM model. In this work, we explore the possibility of explaining the EDGES anomaly in terms of modified dispersion relations. The latter are typically induced in unified theories and theories of quantum gravity, such as String/M-theories and Loop Quantum Gravity. These modified dispersion relations affect the density of states per unit volume and thus the thermal spectrum of the Cosmic Microwave Background photons. The temperature of the 21-cm brightness temperature is modified accordingly giving a potential explanation of the EDGES anomaly.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.