23 research outputs found

    Searching for axion-like time-dependent cosmic birefringence with SPT-3G

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    Ultralight axion-like particles (ALPs) are compelling dark matter candidates because of their potential to resolve small-scale discrepancies between Λ\LambdaCDM predictions and cosmological observations. Axion-photon coupling induces a polarization rotation in linearly polarized photons traveling through an ALP field; thus, as the local ALP dark matter field oscillates in time, distant static polarized sources will appear to oscillate with a frequency proportional to the ALP mass. We use observations of the cosmic microwave background from SPT-3G, the current receiver on the South Pole Telescope, to set upper limits on the value of the axion-photon coupling constant gϕγg_{\phi\gamma} over the approximate mass range 1022101910^{-22} - 10^{-19} eV, corresponding to oscillation periods from 12 hours to 100 days. For periods between 1 and 100 days (4.7×1022 eVmϕ4.7×1020 eV4.7 \times 10^{-22} \text{ eV} \leq m_\phi \leq 4.7 \times 10^{-20} \text{ eV}), where the limit is approximately constant, we set a median 95% C.L. upper limit on the amplitude of on-sky polarization rotation of 0.071 deg. Assuming that dark matter comprises a single ALP species with a local dark matter density of 0.3 GeV/cm30.3 \text{ GeV/cm}^3, this corresponds to gϕγ<1.18×1012 GeV1×(mϕ1.0×1021 eV)g_{\phi\gamma} < 1.18 \times 10^{-12}\text{ GeV}^{-1} \times \left( \frac{m_{\phi}}{1.0 \times 10^{-21} \text{ eV}} \right). These new limits represent an improvement over the previous strongest limits set using the same effect by a factor of ~3.8

    Novel Small Molecules in the Treatment of Lymphomas

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