TY - JOUR
T1 - Galactic rotation curves versus ultralight dark matter
T2 - implications of the soliton-host halo relation
AU - Bar, Nitsan
AU - Blas, Diego
AU - Blum, Kfir
AU - Sibiryakov, Sergey
PY - 2018/10/31
Y1 - 2018/10/31
N2 - Bosonic ultra-light dark matter (ULDM) would form cored density distributions at the center of galaxies. These cores, seen in numerical simulations, admit analytic description as the lowest energy bound state solution ("soliton") of the Schroedinger-Poisson equations. Numerical simulations of ULDM galactic halos found empirical scaling relations between the mass of the large-scale host halo and the mass of the central soliton. We discuss how the simulation results of different groups can be understood in terms of the basic properties of the soliton. Importantly, simulations imply that the energy per unit mass in the soliton and in the virialised host halo should be approximately equal. This relation lends itself to observational tests, because it predicts that the peak circular velocity, measured for the host halo in the outskirts of the galaxy, should approximately repeat itself in the central region. Contrasting this prediction to the measured rotation curves of well-resolved near-by galaxies, we show that ULDM in the mass range $m\sim (10^{-22}\div 10^{-21})$ eV, which has been invoked as a possible solution to the small-scale puzzles of $\Lambda$CDM, is in tension with the data. We suggest that a dedicated analysis of the Milky Way inner gravitational potential could probe ULDM up to $m\lesssim 10^{-19}$ eV.
AB - Bosonic ultra-light dark matter (ULDM) would form cored density distributions at the center of galaxies. These cores, seen in numerical simulations, admit analytic description as the lowest energy bound state solution ("soliton") of the Schroedinger-Poisson equations. Numerical simulations of ULDM galactic halos found empirical scaling relations between the mass of the large-scale host halo and the mass of the central soliton. We discuss how the simulation results of different groups can be understood in terms of the basic properties of the soliton. Importantly, simulations imply that the energy per unit mass in the soliton and in the virialised host halo should be approximately equal. This relation lends itself to observational tests, because it predicts that the peak circular velocity, measured for the host halo in the outskirts of the galaxy, should approximately repeat itself in the central region. Contrasting this prediction to the measured rotation curves of well-resolved near-by galaxies, we show that ULDM in the mass range $m\sim (10^{-22}\div 10^{-21})$ eV, which has been invoked as a possible solution to the small-scale puzzles of $\Lambda$CDM, is in tension with the data. We suggest that a dedicated analysis of the Milky Way inner gravitational potential could probe ULDM up to $m\lesssim 10^{-19}$ eV.
KW - Astrophysics - Cosmology and Nongalactic Astrophysics
KW - High Energy Physics - Phenomenology
KW - Astrophysics - Astrophysics of Galaxies
U2 - 10.1103/PhysRevD.98.083027
DO - 10.1103/PhysRevD.98.083027
M3 - Article
VL - 98
JO - Physical Review D (Particles, Fields, Gravitation and Cosmology)
JF - Physical Review D (Particles, Fields, Gravitation and Cosmology)
SN - 1550-7998
M1 - 083027
ER -
TY - JOUR
T1 - Scattering of scalar, electromagnetic, and gravitational waves from binary systems
AU - Annulli, Lorenzo
AU - Bernard, Laura
AU - Blas, Diego
AU - Cardoso, Vitor
N1 - 19 pages, 3 figures, to appear in PRD
PY - 2018/10/1
Y1 - 2018/10/1
N2 - The direct detection of gravitational waves crowns decades of efforts in the modeling of sources and of increasing detectors’ sensitivity. With future third-generation Earth-based detectors or space-based observatories, gravitational-wave astronomy will be at its full bloom. Previously brushed-aside questions on environmental or other systematic effects in the generation and propagation of gravitational waves are now begging for a systematic treatment. Here, we study how electromagnetic and gravitational radiation is scattered by a binary system. Scattering cross sections, resonances and the effect of an impinging wave on a gravitational-bound binary are worked out for the first time. The ratio between the scattered-wave amplitude and the incident wave can be of order 10−5 for known pulsars, bringing this into the realm of future gravitational-wave observatories. For currently realistic distribution of compact-object binaries, the interaction cross section is too small to be of relevance.
AB - The direct detection of gravitational waves crowns decades of efforts in the modeling of sources and of increasing detectors’ sensitivity. With future third-generation Earth-based detectors or space-based observatories, gravitational-wave astronomy will be at its full bloom. Previously brushed-aside questions on environmental or other systematic effects in the generation and propagation of gravitational waves are now begging for a systematic treatment. Here, we study how electromagnetic and gravitational radiation is scattered by a binary system. Scattering cross sections, resonances and the effect of an impinging wave on a gravitational-bound binary are worked out for the first time. The ratio between the scattered-wave amplitude and the incident wave can be of order 10−5 for known pulsars, bringing this into the realm of future gravitational-wave observatories. For currently realistic distribution of compact-object binaries, the interaction cross section is too small to be of relevance.
KW - General Relativity and Quantum Cosmology, High Energy Physics - Theory
U2 - 10.1103/PhysRevD.98.084001
DO - 10.1103/PhysRevD.98.084001
M3 - Article
VL - 98
SP - 084001
JO - Physical Review D (Particles, Fields, Gravitation and Cosmology)
JF - Physical Review D (Particles, Fields, Gravitation and Cosmology)
SN - 1550-7998
ER -
TY - JOUR
T1 - Renormalization of gauge theories in the background-field approach
AU - Barvinsky, Andrei O.
AU - Blas, Diego
AU - Herrero-Valea, Mario
AU - Sibiryakov, Sergey M.
AU - Steinwachs, Christian F.
PY - 2018/7/5
Y1 - 2018/7/5
N2 - Using the background-field method we demonstrate the Becchi-Rouet-Stora-Tyutin (BRST) structure of counterterms in a broad class of gauge theories. Put simply, we show that gauge invariance is preserved by renormalization in local gauge field theories whenever they admit a sensible background-field formulation and anomaly-free path integral measure. This class encompasses Yang-Mills theories (with possibly Abelian subgroups) and relativistic gravity, including both renormalizable and non-renormalizable (effective) theories. Our results also hold for non-relativistic models such as Yang-Mills theories with anisotropic scaling or Hořava gravity. They strengthen and generalize the existing results in the literature concerning the renormalization of gauge systems. Locality of the BRST construction is emphasized throughout the derivation. We illustrate our general approach with several explicit examples.
AB - Using the background-field method we demonstrate the Becchi-Rouet-Stora-Tyutin (BRST) structure of counterterms in a broad class of gauge theories. Put simply, we show that gauge invariance is preserved by renormalization in local gauge field theories whenever they admit a sensible background-field formulation and anomaly-free path integral measure. This class encompasses Yang-Mills theories (with possibly Abelian subgroups) and relativistic gravity, including both renormalizable and non-renormalizable (effective) theories. Our results also hold for non-relativistic models such as Yang-Mills theories with anisotropic scaling or Hořava gravity. They strengthen and generalize the existing results in the literature concerning the renormalization of gauge systems. Locality of the BRST construction is emphasized throughout the derivation. We illustrate our general approach with several explicit examples.
KW - BRST Quantization, Effective Field Theories, Gauge Symmetry, Models of Quantum Gravity, High Energy Physics - Theory, General Relativity and Quantum Cosmology
U2 - 10.1007/JHEP07(2018)035
DO - 10.1007/JHEP07(2018)035
M3 - Article
VL - 2018
SP - 35
JO - Journal of High Energy Physics
JF - Journal of High Energy Physics
SN - 1126-6708
ER -