Does the high-energy AMS-02 positron flux originate from the dark matter density spikes around nearby black holes?

Man Ho Chan; Chak Man Lee

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arXiv · 2509.01860

Does the high-energy AMS-02 positron flux originate from the dark matter density spikes around nearby black holes?

Man Ho Chan·Chak Man Lee

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Abstract

Recent measurements made by the Alpha Magnetic Spectrometer (AMS) have detected accurate positron flux for energy range 1-1000 GeV. The energy spectrum can be best described by two source terms: the low-energy background diffusion term and an unknown high-energy source term. In this article, we discuss the possibility of the emission of positrons originating from dark matter annihilation in two nearby black hole X-ray binaries A0620-00 and XTE J1118+480. We show that the dark matter density spikes around these two black holes can best produce the observed AMS-02 high-energy positron flux due to dark matter annihilation with rest mass $m_{\rm DM} \approx 8000$ GeV via the $W^+W^-$ annihilation channel. This initiates a new proposal to account for the unknown high-energy source term in the AMS-02 positron spectrum.

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Man Ho Chan, Chak Man Lee. 2025-09-02. Does the high-energy AMS-02 positron flux originate from the dark matter density spikes around nearby black holes?. https://arxiv.org/abs/2509.01860

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