We present detailed forecasts for the constraints on the characteristics of primordial magnetic f... more We present detailed forecasts for the constraints on the characteristics of primordial magnetic fields (PMFs) generated prior to recombination that will be obtained with the LiteBIRD satellite. The constraints are driven by some of the main physical effects of PMFs on the CMB anisotropies: the gravitational effects of magnetically-induced perturbations; the effects on the thermal and ionization history of the Universe; the Faraday rotation imprint on the CMB polarization spectra; and the non-Gaussianities induced in polarization anisotropies. LiteBIRD represents a sensitive probe for PMFs. We explore different levels of complexity, for LiteBIRD data and PMF configurations, accounting for possible degeneracies with primordial gravitational waves from inflation. By exploiting all the physical effects, LiteBIRD will be able to improve the current limit on PMFs at intermediate and large scales coming from Planck. In particular, thanks to its accurate B-mode polarization measurement, LiteBIRD will improve the constraints on infrared configurations for the gravitational effect, giving B n B =−2.9 1 Mpc < 0.8 nG at 95% C.L., potentially opening the possibility to detect nanogauss fields with high significance. We also observe a significant improvement in the limits when marginalized over the spectral index, B marg 1 Mpc < 2.2 nG at 95 % C.L. From the thermal history effect, which relies mainly on E-mode polarization data, we obtain a significant improvement for all PMF configurations, with the marginalized case, ⟨B 2 ⟩ marg < 0.50 nG at 95 % C.L. Faraday rotation constraints will take advantage of the wide frequency coverage of LiteBIRD and the high sensitivity in B modes, improving the limits by orders of magnitude with respect to current results, B n B =−2.9 1 Mpc < 3.2 nG at 95 % C.L. Finally, non-Gaussianities of the B-mode polarization can probe PMFs at the level of 1 nG, again significantly improving the current bounds from Planck. Altogether our forecasts represent a broad collection of complementary probes based on widely tested methodologies, providing conservative limits on PMF characteristics that will be achieved with the LiteBIRD satellite.
We consider the polarized Sunyaev-Zel'dovich (pSZ) effect for a tomographic probe of cosmic biref... more We consider the polarized Sunyaev-Zel'dovich (pSZ) effect for a tomographic probe of cosmic birefringence, including all relevant terms of the pSZ effect in the cosmic microwave background (CMB) observables, some of which were ignored in the previous works. The pSZ effect produces late-time polarization signals from the scattering of the local temperature quadrupole seen by an electron. We forecast the expected constraints on cosmic birefringence at the late time of the universe with the pSZ effect. We find that the birefringence angles at 2 ≲ z ≲ 5 are constrained at a subdegree level by the crosscorrelations between CMB E and B modes or between CMB B modes and remote quadrupole E modes using data from LiteBIRD, CMB-S4, and LSST. In particular, the cross-correlation between large-scale CMB B modes and remote-quadrupole E modes has a much smaller bias from the Galactic foregrounds and is useful to cross-check the results from the EB power spectrum.
We explore a mechanism to produce a light dark photon dark matter through a coupling between the ... more We explore a mechanism to produce a light dark photon dark matter through a coupling between the dark photon field and a spectator scalar field which plays no role in the inflationary expansion of the Universe while rolling down its potential during the inflation. The motion of the spectator field efficiently produces dark photons with large wavelengths which become non-relativistic before the time of matter-radiation equality. The spectrum of the wavelengths is peaky so that the constraint from the isocurvature perturbation can be evaded. The correct relic abundance is then achieved over a wide range of the dark photon mass down to 10 −13 eV. Our mechanism favors high-scale inflation models which can be tested in future observations. Furthermore, fluctuations of the dark photon field during inflation produce gravitational waves detectable at future space-based interferometers and/or pulsar timing array experiments.
The recent analysis of the Planck 2018 polarization data shows a nonzero isotropic cosmic birefri... more The recent analysis of the Planck 2018 polarization data shows a nonzero isotropic cosmic birefringence (ICB) that is not explained within the ΛCDM paradigm. We then explore the question of whether the nonzero ICB is interpreted by the framework of the Standard Model Effective Field Theory (SMEFT), or at the energy scales of the cosmic microwave background, the low-energy EFT (LEFT) whose dynamical degrees of freedom are five SM quarks and all neutral and charged leptons. Our systematic study reveals that any operator in the EFT on a cosmological background would not give the reported ICB angle, which is observationally consistent with frequency independence. In particular, we estimate the size of the ICB angle generated by the effect that the cosmic microwave background photons travel through the medium of the cosmic neutrino background with parity-violating neutrino-photon interactions and find that it would be too small to explain the data. If the reported ICB angle should be confirmed, then our result would indicate the existence of a new particle that is lighter than the electroweak scale and feebly interacting with the SM particles.
We suggest a novel experimental method to search for axion dark matter with an optical ring cavit... more We suggest a novel experimental method to search for axion dark matter with an optical ring cavity. Our cavity measures the difference of the resonant frequencies between two circular-polarizations of the laser beam. Its technical design adopts double-pass configuration to realize a null experiment and reject environmental common-mode noises. We reveal that it can probe the axion-photon coupling constant with a broad range of axion mass 10 −17 eV m 10 −10 eV, up to several orders of magnitude beyond the current limits. We expect that this cavity experiment establishes a new window to develop the axion research.
Dark matter Axion search with riNg Cavity Experiment (DANCE) was proposed to search for axion dar... more Dark matter Axion search with riNg Cavity Experiment (DANCE) was proposed to search for axion dark matter [Phys. Rev. Lett. 121, 161301 (2018)]. We aim to detect the rotation and oscillation of optical linear polarization caused by axion-photon coupling with a bow-tie cavity. DANCE can improve the sensitivity to axion-photon coupling constant gaγ for axion mass ma < 10 −10 eV by several orders of magnitude compared to the best upper limits at present. A prototype experiment DANCE Act-1 is ongoing to demonstrate the feasibility of the method and to investigate technical noises. The optics was assembled and the performance of the cavity was evaluated. The first 12-day observation was successfully performed in May 2021. We reached 3 × 10 −6 rad/ √ Hz at 10 Hz in the one-sided amplitude spectral density of the rotation angle of linear polarization.
Journal of Cosmology and Astroparticle Physics, Sep 1, 2022
We show that a recent constraint on the cosmic birefringence effect due to dark energy can be rel... more We show that a recent constraint on the cosmic birefringence effect due to dark energy can be related to the constraints on the coupling of axion dark matter to photon, by relying on a simple model of two-axion alignment mechanism with periodic potentials. Owing to the alignment of the potentials, one linear combination of two fields provides a nearly flat direction and acts as dark energy, whereas the other combination provides a steep direction and acts as dark matter. This scenario solves the known conceptual issues of one-field model for dark energy and predicts the connection between seemingly disparate constraints on the dark sectors of our universe.
Axion dark matter differentiates the phase velocities of the circular-polarized photons. In [Phys... more Axion dark matter differentiates the phase velocities of the circular-polarized photons. In [Phys. Rev. Lett. 123, 111301 (2019)], we have proposed a scheme to measure the phase difference by using a linear optical cavity. If the scheme is applied to the Fabry-Pérot arm of Advanced LIGO-like (Cosmic-Explorer-like) gravitational wave detector, the potential sensitivity to the axion-photon coupling constant, gaγ, reaches gaγ 8 × 10 −13 GeV −1 (4 × 10 −14 GeV −1) at the axion mass m 3 × 10 −13 eV (2 × 10 −15 eV) and remains at around this sensitivity for 3 orders of magnitude in mass. Furthermore, its sensitivity has a sharp peak reaching gaγ 10 −14 GeV −1 (8 × 10 −17 GeV −1) at m = 1.563 × 10 −10 eV (1.563 × 10 −11 eV). This sensitivity can be achieved without loosing any sensitivity to gravitational waves.
Antisymmetric tensor field (two-form field) is a ubiquitous component in string theory and genera... more Antisymmetric tensor field (two-form field) is a ubiquitous component in string theory and generally couples to the scalar sector through its kinetic term. In this paper, we propose a cosmological scenario that the particle production of two-form field, which is triggered by the background motion of the coupled inflaton field, occurs at the intermediate stage of inflation and generates the sizable amount of primordial black holes as dark matter after inflation. We also compute the secondary gravitational waves sourced by the curvature perturbation and show that the resultant power spectra are testable with the future spacebased laser interferometers.
We demonstrate that the recently announced signal for a stochastic gravitational wave background ... more We demonstrate that the recently announced signal for a stochastic gravitational wave background (SGWB) from pulsar timing array (PTA) observations, if attributed to new physics, is compatible with primordial GW production due to axion-gauge dynamics during inflation. More specifically we find that axion-U (1) models may lead to sufficient particle production to explain the signal while simultaneously source some fraction of sub-solar mass primordial black holes (PBHs) as a signature. Moreover there is a parity violation in GW sector, hence the model suggests chiral GW search as a concrete target for future. We further analyze the axion-SU (2) coupling signatures and find that in the low/mild backreaction regime, it is incapable of producing PTA evidence and the tensor-to-scalar ratio is low at the peak, hence it overproduces scalar perturbations and PBHs.
with a collaboration name incorrectly inserted after the author list. "CLEO Collaboration" has be... more with a collaboration name incorrectly inserted after the author list. "CLEO Collaboration" has been removed as of 3 May 2017. The collaboration name is present in the printed version of the journal.
We consider the polarized Sunyaev-Zel'dovich (pSZ) effect for a tomographic probe of cosmic biref... more We consider the polarized Sunyaev-Zel'dovich (pSZ) effect for a tomographic probe of cosmic birefringence, including all relevant terms of the pSZ effect in the cosmic microwave background (CMB) observables, some of which were ignored in the previous works. The pSZ effect produces late-time polarization signals from the scattering of the local temperature quadrupole seen by an electron. We forecast the expected constraints on cosmic birefringence at the late time of the universe with the pSZ effect. We find that the birefringence angles at 2 ≲ z ≲ 5 are constrained at a subdegree level by the cross-correlations between CMB Eand B-modes or between CMB B-modes and remote quadrupole E-modes using data from LiteBIRD, CMB-S4, and LSST. In particular, the cross-correlation between large-scale CMB B-modes and remote-quadrupole E-modes has a much smaller bias from the Galactic foregrounds and is useful to cross-check the results from the EB power spectrum.
Recently, several studies have pointed out that gravitational-wave detectors are sensitive to ult... more Recently, several studies have pointed out that gravitational-wave detectors are sensitive to ultralight vector dark matter and can improve the current best constraints given by the equivalence principle tests. While a gravitational-wave detector is a highly precise measuring tool for the length difference of its arms, its sensitivity is limited because the displacements of its test mass mirrors caused by vector dark matter are almost common. In this paper, we point out that the sensitivity is significantly improved if the effect of finite light-traveling time in the detector's arms is taken into account. This effect enables advanced LIGO to improve the constraints on the Uð1Þ B−L gauge coupling by an order of magnitude compared with the current best constraints. It also makes the sensitivities of the future gravitational-wave detectors overwhelmingly better than the current ones. The factor by which the constraints are improved due to the new effect depends on the mass of the vector dark matter, and the maximum improvement factors are 470, 880, 1600, 180, and 1400 for advanced LIGO, Einstein Telescope, Cosmic Explorer, DECIGO, and LISA, respectively. Including the new effect, we update the constraints given by the first observing run of advanced LIGO and improve the constraints on the Uð1Þ B gauge coupling by an order of magnitude compared with the current best constraints.
Axion-like particles (ALPs) are pseudo-scalar particles that are candidates for ultralight dark m... more Axion-like particles (ALPs) are pseudo-scalar particles that are candidates for ultralight dark matter. ALPs interact with photons slightly and cause the rotational oscillation of linear polarization. DANCE searches for ALP dark matter by enhancing the rotational oscillation in a bow-tie ring cavity. The signal to noise ratio of DANCE can be improved by longterm observation, and we are planning a year-long observation for the final DANCE. In this document, I will report on the control systems of the ring cavity we developed for the future long-term observation.
Dark matter Axion search with riNg Cavity Experiment (DANCE) was proposed. To search for axion-li... more Dark matter Axion search with riNg Cavity Experiment (DANCE) was proposed. To search for axion-like particles, we aim to detect the rotation and oscillation of optical linear polarization caused by axion-photon coupling with a bow-tie cavity. DANCE can improve the sensitivity to axion-photon coupling constant gaγ for axion mass ma < 10 −10 eV by several orders of magnitude compared to the best upper limits at present. A prototype experiment DANCE Act-1 is in progress to demonstrate the feasibility of the method and to investigate technical noises. We assembled the optics, evaluated the performance of the cavity, and estimated the current sensitivity. If we observe for a year, we can reach gaγ 9 × 10 −7 GeV −1 at ma 10 −13 eV. The current sensitivity was believed to be limited by laser intensity noise at low frequencies and by mechanical vibration at high frequencies.
Monthly Notices of the Royal Astronomical Society, 2019
Ultralight-axion (ULA) dark matter is one of the possible solutions to resolve smallscale problem... more Ultralight-axion (ULA) dark matter is one of the possible solutions to resolve smallscale problems, especially the core-cusp problem. This is because ULA dark matter can create a central soliton core in all dark matter haloes stemmed from the quantum pressure against gravity below the de Broglie wavelength, which becomes manifest on astrophysical scales with axion mass range ∼ 10 −22 eV. In this work, we apply our nonspherical dynamical models to the kinematic data of eight classical dwarf spheroidals (dSphs) to obtain more reliable and realistic limits on ULA particle mass. This is motivated by the reasons that the light distributions of the dSphs is not spherical, nor are the shapes of dark matter haloes predicted by ULA dark matter simulations. Compared with the previous studies on ULA dark matter assuming spherical mass models, our result is less stringent than those constraints due to the uncertainties on non-sphericity. On the other hand, remarkably, we find that the dSphs would prefer to have a flattened dark matter halo rather than a spherical one, especially Draco favours a strongly elongated dark matter halo caused naively by the assumption of a soliton-core profile. Moreover, our consequent non-spherical core profiles are much more flattened than numerical predictions based on ULA dark matter, even though there are still uncertainties on the estimation of dark matter halo structure. To alleviate this discrepancy, further understanding of baryonic and/or ULA dark matter physics on small mass scales might be needed.
We explore a mechanism to produce a light dark photon dark matter through a coupling between the ... more We explore a mechanism to produce a light dark photon dark matter through a coupling between the dark photon field and a spectator scalar field which plays no role in the inflationary expansion of the Universe while rolling down its potential during the inflation. The motion of the spectator field efficiently produces dark photons with large wavelengths which become non-relativistic before the time of matter-radiation equality. The spectrum of the wavelengths is peaky so that the constraint from the isocurvature perturbation can be evaded. The correct relic abundance is then achieved over a wide range of the dark photon mass down to 10-13 eV. Our mechanism favors high-scale inflation models which can be tested in future observations. Furthermore, fluctuations of the dark photon field during inflation produce gravitational waves detectable at future space-based interferometers and/or pulsar timing array experiments.
Axions are one of the well-motivated candidates for dark matter, originally proposed to solve the... more Axions are one of the well-motivated candidates for dark matter, originally proposed to solve the strong CP problem in particle physics. Dark matter Axion search with riNg Cavity Experiment (DANCE) is a new experimental project to broadly search for axion dark matter in the mass range of 10 −17 eV < ma < 10 −11 eV. We aim to detect the rotational oscillation of linearly polarized light caused by the axion-photon coupling with a bow-tie cavity. The first results of the prototype experiment, DANCE Act-1, are reported from a 24-hour observation. We found no evidence for axions and set 95% confidence level upper limit on the axion-photon coupling gaγγ ≲ 8×10 −4 GeV −1 in 10 −14 eV < ma < 10 −13 eV. Although the bound did not exceed the current best limits, this optical cavity experiment is the first demonstration of polarization-based axion dark matter search without any external magnetic field.
Acknowledgement 16 A. Fourier transformation of field value and its derivative 16 B. Signals of d... more Acknowledgement 16 A. Fourier transformation of field value and its derivative 16 B. Signals of dark photon in interferometer 18 C. Likelihood in a deterministic and a stochastic case. 19 D. Approximate formula for short-and long-time measurements 20 References 22
We present detailed forecasts for the constraints on the characteristics of primordial magnetic f... more We present detailed forecasts for the constraints on the characteristics of primordial magnetic fields (PMFs) generated prior to recombination that will be obtained with the LiteBIRD satellite. The constraints are driven by some of the main physical effects of PMFs on the CMB anisotropies: the gravitational effects of magnetically-induced perturbations; the effects on the thermal and ionization history of the Universe; the Faraday rotation imprint on the CMB polarization spectra; and the non-Gaussianities induced in polarization anisotropies. LiteBIRD represents a sensitive probe for PMFs. We explore different levels of complexity, for LiteBIRD data and PMF configurations, accounting for possible degeneracies with primordial gravitational waves from inflation. By exploiting all the physical effects, LiteBIRD will be able to improve the current limit on PMFs at intermediate and large scales coming from Planck. In particular, thanks to its accurate B-mode polarization measurement, LiteBIRD will improve the constraints on infrared configurations for the gravitational effect, giving B n B =−2.9 1 Mpc < 0.8 nG at 95% C.L., potentially opening the possibility to detect nanogauss fields with high significance. We also observe a significant improvement in the limits when marginalized over the spectral index, B marg 1 Mpc < 2.2 nG at 95 % C.L. From the thermal history effect, which relies mainly on E-mode polarization data, we obtain a significant improvement for all PMF configurations, with the marginalized case, ⟨B 2 ⟩ marg < 0.50 nG at 95 % C.L. Faraday rotation constraints will take advantage of the wide frequency coverage of LiteBIRD and the high sensitivity in B modes, improving the limits by orders of magnitude with respect to current results, B n B =−2.9 1 Mpc < 3.2 nG at 95 % C.L. Finally, non-Gaussianities of the B-mode polarization can probe PMFs at the level of 1 nG, again significantly improving the current bounds from Planck. Altogether our forecasts represent a broad collection of complementary probes based on widely tested methodologies, providing conservative limits on PMF characteristics that will be achieved with the LiteBIRD satellite.
We consider the polarized Sunyaev-Zel'dovich (pSZ) effect for a tomographic probe of cosmic biref... more We consider the polarized Sunyaev-Zel'dovich (pSZ) effect for a tomographic probe of cosmic birefringence, including all relevant terms of the pSZ effect in the cosmic microwave background (CMB) observables, some of which were ignored in the previous works. The pSZ effect produces late-time polarization signals from the scattering of the local temperature quadrupole seen by an electron. We forecast the expected constraints on cosmic birefringence at the late time of the universe with the pSZ effect. We find that the birefringence angles at 2 ≲ z ≲ 5 are constrained at a subdegree level by the crosscorrelations between CMB E and B modes or between CMB B modes and remote quadrupole E modes using data from LiteBIRD, CMB-S4, and LSST. In particular, the cross-correlation between large-scale CMB B modes and remote-quadrupole E modes has a much smaller bias from the Galactic foregrounds and is useful to cross-check the results from the EB power spectrum.
We explore a mechanism to produce a light dark photon dark matter through a coupling between the ... more We explore a mechanism to produce a light dark photon dark matter through a coupling between the dark photon field and a spectator scalar field which plays no role in the inflationary expansion of the Universe while rolling down its potential during the inflation. The motion of the spectator field efficiently produces dark photons with large wavelengths which become non-relativistic before the time of matter-radiation equality. The spectrum of the wavelengths is peaky so that the constraint from the isocurvature perturbation can be evaded. The correct relic abundance is then achieved over a wide range of the dark photon mass down to 10 −13 eV. Our mechanism favors high-scale inflation models which can be tested in future observations. Furthermore, fluctuations of the dark photon field during inflation produce gravitational waves detectable at future space-based interferometers and/or pulsar timing array experiments.
The recent analysis of the Planck 2018 polarization data shows a nonzero isotropic cosmic birefri... more The recent analysis of the Planck 2018 polarization data shows a nonzero isotropic cosmic birefringence (ICB) that is not explained within the ΛCDM paradigm. We then explore the question of whether the nonzero ICB is interpreted by the framework of the Standard Model Effective Field Theory (SMEFT), or at the energy scales of the cosmic microwave background, the low-energy EFT (LEFT) whose dynamical degrees of freedom are five SM quarks and all neutral and charged leptons. Our systematic study reveals that any operator in the EFT on a cosmological background would not give the reported ICB angle, which is observationally consistent with frequency independence. In particular, we estimate the size of the ICB angle generated by the effect that the cosmic microwave background photons travel through the medium of the cosmic neutrino background with parity-violating neutrino-photon interactions and find that it would be too small to explain the data. If the reported ICB angle should be confirmed, then our result would indicate the existence of a new particle that is lighter than the electroweak scale and feebly interacting with the SM particles.
We suggest a novel experimental method to search for axion dark matter with an optical ring cavit... more We suggest a novel experimental method to search for axion dark matter with an optical ring cavity. Our cavity measures the difference of the resonant frequencies between two circular-polarizations of the laser beam. Its technical design adopts double-pass configuration to realize a null experiment and reject environmental common-mode noises. We reveal that it can probe the axion-photon coupling constant with a broad range of axion mass 10 −17 eV m 10 −10 eV, up to several orders of magnitude beyond the current limits. We expect that this cavity experiment establishes a new window to develop the axion research.
Dark matter Axion search with riNg Cavity Experiment (DANCE) was proposed to search for axion dar... more Dark matter Axion search with riNg Cavity Experiment (DANCE) was proposed to search for axion dark matter [Phys. Rev. Lett. 121, 161301 (2018)]. We aim to detect the rotation and oscillation of optical linear polarization caused by axion-photon coupling with a bow-tie cavity. DANCE can improve the sensitivity to axion-photon coupling constant gaγ for axion mass ma < 10 −10 eV by several orders of magnitude compared to the best upper limits at present. A prototype experiment DANCE Act-1 is ongoing to demonstrate the feasibility of the method and to investigate technical noises. The optics was assembled and the performance of the cavity was evaluated. The first 12-day observation was successfully performed in May 2021. We reached 3 × 10 −6 rad/ √ Hz at 10 Hz in the one-sided amplitude spectral density of the rotation angle of linear polarization.
Journal of Cosmology and Astroparticle Physics, Sep 1, 2022
We show that a recent constraint on the cosmic birefringence effect due to dark energy can be rel... more We show that a recent constraint on the cosmic birefringence effect due to dark energy can be related to the constraints on the coupling of axion dark matter to photon, by relying on a simple model of two-axion alignment mechanism with periodic potentials. Owing to the alignment of the potentials, one linear combination of two fields provides a nearly flat direction and acts as dark energy, whereas the other combination provides a steep direction and acts as dark matter. This scenario solves the known conceptual issues of one-field model for dark energy and predicts the connection between seemingly disparate constraints on the dark sectors of our universe.
Axion dark matter differentiates the phase velocities of the circular-polarized photons. In [Phys... more Axion dark matter differentiates the phase velocities of the circular-polarized photons. In [Phys. Rev. Lett. 123, 111301 (2019)], we have proposed a scheme to measure the phase difference by using a linear optical cavity. If the scheme is applied to the Fabry-Pérot arm of Advanced LIGO-like (Cosmic-Explorer-like) gravitational wave detector, the potential sensitivity to the axion-photon coupling constant, gaγ, reaches gaγ 8 × 10 −13 GeV −1 (4 × 10 −14 GeV −1) at the axion mass m 3 × 10 −13 eV (2 × 10 −15 eV) and remains at around this sensitivity for 3 orders of magnitude in mass. Furthermore, its sensitivity has a sharp peak reaching gaγ 10 −14 GeV −1 (8 × 10 −17 GeV −1) at m = 1.563 × 10 −10 eV (1.563 × 10 −11 eV). This sensitivity can be achieved without loosing any sensitivity to gravitational waves.
Antisymmetric tensor field (two-form field) is a ubiquitous component in string theory and genera... more Antisymmetric tensor field (two-form field) is a ubiquitous component in string theory and generally couples to the scalar sector through its kinetic term. In this paper, we propose a cosmological scenario that the particle production of two-form field, which is triggered by the background motion of the coupled inflaton field, occurs at the intermediate stage of inflation and generates the sizable amount of primordial black holes as dark matter after inflation. We also compute the secondary gravitational waves sourced by the curvature perturbation and show that the resultant power spectra are testable with the future spacebased laser interferometers.
We demonstrate that the recently announced signal for a stochastic gravitational wave background ... more We demonstrate that the recently announced signal for a stochastic gravitational wave background (SGWB) from pulsar timing array (PTA) observations, if attributed to new physics, is compatible with primordial GW production due to axion-gauge dynamics during inflation. More specifically we find that axion-U (1) models may lead to sufficient particle production to explain the signal while simultaneously source some fraction of sub-solar mass primordial black holes (PBHs) as a signature. Moreover there is a parity violation in GW sector, hence the model suggests chiral GW search as a concrete target for future. We further analyze the axion-SU (2) coupling signatures and find that in the low/mild backreaction regime, it is incapable of producing PTA evidence and the tensor-to-scalar ratio is low at the peak, hence it overproduces scalar perturbations and PBHs.
with a collaboration name incorrectly inserted after the author list. "CLEO Collaboration" has be... more with a collaboration name incorrectly inserted after the author list. "CLEO Collaboration" has been removed as of 3 May 2017. The collaboration name is present in the printed version of the journal.
We consider the polarized Sunyaev-Zel'dovich (pSZ) effect for a tomographic probe of cosmic biref... more We consider the polarized Sunyaev-Zel'dovich (pSZ) effect for a tomographic probe of cosmic birefringence, including all relevant terms of the pSZ effect in the cosmic microwave background (CMB) observables, some of which were ignored in the previous works. The pSZ effect produces late-time polarization signals from the scattering of the local temperature quadrupole seen by an electron. We forecast the expected constraints on cosmic birefringence at the late time of the universe with the pSZ effect. We find that the birefringence angles at 2 ≲ z ≲ 5 are constrained at a subdegree level by the cross-correlations between CMB Eand B-modes or between CMB B-modes and remote quadrupole E-modes using data from LiteBIRD, CMB-S4, and LSST. In particular, the cross-correlation between large-scale CMB B-modes and remote-quadrupole E-modes has a much smaller bias from the Galactic foregrounds and is useful to cross-check the results from the EB power spectrum.
Recently, several studies have pointed out that gravitational-wave detectors are sensitive to ult... more Recently, several studies have pointed out that gravitational-wave detectors are sensitive to ultralight vector dark matter and can improve the current best constraints given by the equivalence principle tests. While a gravitational-wave detector is a highly precise measuring tool for the length difference of its arms, its sensitivity is limited because the displacements of its test mass mirrors caused by vector dark matter are almost common. In this paper, we point out that the sensitivity is significantly improved if the effect of finite light-traveling time in the detector's arms is taken into account. This effect enables advanced LIGO to improve the constraints on the Uð1Þ B−L gauge coupling by an order of magnitude compared with the current best constraints. It also makes the sensitivities of the future gravitational-wave detectors overwhelmingly better than the current ones. The factor by which the constraints are improved due to the new effect depends on the mass of the vector dark matter, and the maximum improvement factors are 470, 880, 1600, 180, and 1400 for advanced LIGO, Einstein Telescope, Cosmic Explorer, DECIGO, and LISA, respectively. Including the new effect, we update the constraints given by the first observing run of advanced LIGO and improve the constraints on the Uð1Þ B gauge coupling by an order of magnitude compared with the current best constraints.
Axion-like particles (ALPs) are pseudo-scalar particles that are candidates for ultralight dark m... more Axion-like particles (ALPs) are pseudo-scalar particles that are candidates for ultralight dark matter. ALPs interact with photons slightly and cause the rotational oscillation of linear polarization. DANCE searches for ALP dark matter by enhancing the rotational oscillation in a bow-tie ring cavity. The signal to noise ratio of DANCE can be improved by longterm observation, and we are planning a year-long observation for the final DANCE. In this document, I will report on the control systems of the ring cavity we developed for the future long-term observation.
Dark matter Axion search with riNg Cavity Experiment (DANCE) was proposed. To search for axion-li... more Dark matter Axion search with riNg Cavity Experiment (DANCE) was proposed. To search for axion-like particles, we aim to detect the rotation and oscillation of optical linear polarization caused by axion-photon coupling with a bow-tie cavity. DANCE can improve the sensitivity to axion-photon coupling constant gaγ for axion mass ma < 10 −10 eV by several orders of magnitude compared to the best upper limits at present. A prototype experiment DANCE Act-1 is in progress to demonstrate the feasibility of the method and to investigate technical noises. We assembled the optics, evaluated the performance of the cavity, and estimated the current sensitivity. If we observe for a year, we can reach gaγ 9 × 10 −7 GeV −1 at ma 10 −13 eV. The current sensitivity was believed to be limited by laser intensity noise at low frequencies and by mechanical vibration at high frequencies.
Monthly Notices of the Royal Astronomical Society, 2019
Ultralight-axion (ULA) dark matter is one of the possible solutions to resolve smallscale problem... more Ultralight-axion (ULA) dark matter is one of the possible solutions to resolve smallscale problems, especially the core-cusp problem. This is because ULA dark matter can create a central soliton core in all dark matter haloes stemmed from the quantum pressure against gravity below the de Broglie wavelength, which becomes manifest on astrophysical scales with axion mass range ∼ 10 −22 eV. In this work, we apply our nonspherical dynamical models to the kinematic data of eight classical dwarf spheroidals (dSphs) to obtain more reliable and realistic limits on ULA particle mass. This is motivated by the reasons that the light distributions of the dSphs is not spherical, nor are the shapes of dark matter haloes predicted by ULA dark matter simulations. Compared with the previous studies on ULA dark matter assuming spherical mass models, our result is less stringent than those constraints due to the uncertainties on non-sphericity. On the other hand, remarkably, we find that the dSphs would prefer to have a flattened dark matter halo rather than a spherical one, especially Draco favours a strongly elongated dark matter halo caused naively by the assumption of a soliton-core profile. Moreover, our consequent non-spherical core profiles are much more flattened than numerical predictions based on ULA dark matter, even though there are still uncertainties on the estimation of dark matter halo structure. To alleviate this discrepancy, further understanding of baryonic and/or ULA dark matter physics on small mass scales might be needed.
We explore a mechanism to produce a light dark photon dark matter through a coupling between the ... more We explore a mechanism to produce a light dark photon dark matter through a coupling between the dark photon field and a spectator scalar field which plays no role in the inflationary expansion of the Universe while rolling down its potential during the inflation. The motion of the spectator field efficiently produces dark photons with large wavelengths which become non-relativistic before the time of matter-radiation equality. The spectrum of the wavelengths is peaky so that the constraint from the isocurvature perturbation can be evaded. The correct relic abundance is then achieved over a wide range of the dark photon mass down to 10-13 eV. Our mechanism favors high-scale inflation models which can be tested in future observations. Furthermore, fluctuations of the dark photon field during inflation produce gravitational waves detectable at future space-based interferometers and/or pulsar timing array experiments.
Axions are one of the well-motivated candidates for dark matter, originally proposed to solve the... more Axions are one of the well-motivated candidates for dark matter, originally proposed to solve the strong CP problem in particle physics. Dark matter Axion search with riNg Cavity Experiment (DANCE) is a new experimental project to broadly search for axion dark matter in the mass range of 10 −17 eV < ma < 10 −11 eV. We aim to detect the rotational oscillation of linearly polarized light caused by the axion-photon coupling with a bow-tie cavity. The first results of the prototype experiment, DANCE Act-1, are reported from a 24-hour observation. We found no evidence for axions and set 95% confidence level upper limit on the axion-photon coupling gaγγ ≲ 8×10 −4 GeV −1 in 10 −14 eV < ma < 10 −13 eV. Although the bound did not exceed the current best limits, this optical cavity experiment is the first demonstration of polarization-based axion dark matter search without any external magnetic field.
Acknowledgement 16 A. Fourier transformation of field value and its derivative 16 B. Signals of d... more Acknowledgement 16 A. Fourier transformation of field value and its derivative 16 B. Signals of dark photon in interferometer 18 C. Likelihood in a deterministic and a stochastic case. 19 D. Approximate formula for short-and long-time measurements 20 References 22
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