All matter has a property called dipolar electromagnetic where the dipoles show up as in Earth, North and south poles.
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The discovery of two neutron star-black hole coalescences by LIGO and Virgo brings the total number of likely neutron stars observed in gravitational waves to six. We perform the first inference of the mass distribution of this extragalactic population of neutron stars. In contrast to the bimodal Galactic population detected primarily as radio pulsars, the masses of neutron stars in gravitational-wave binaries are thus far consistent with a uniform distribution, with a greater prevalence of high-mass neutron stars. The maximum mass in the gravitational-wave population agrees with that inferred from the neutron stars in our Galaxy and with expectations from dense matter.
Comments: | 10 pages, 4 figures; abridged version submitted to ApJL |
Subjects: | High Energy Astrophysical Phenomena (astro-ph.HE); General Relativity and Quantum Cosmology (gr-qc) |
Cite as: | arXiv:2107.04559 [astro-ph.HE] |
(or arXiv:2107.04559v2 [astro-ph.HE] for this version) |
Dipolar Bose-Einstein condensates represent a powerful platform for the exploration of quantum many-body phenomena arising from long-range interactions. A series of recent experiments has demonstrated the formation of supersolid states of matter. Subsequent theoretical works have shown that quantum fluctuations can affect the underlying phase transition and may lead to the emergence of supersolids with various lattice structures in dipolar condensates. In this work we explore the signatures of such different geometries in confined finite condensates. In addition to previously found triangular lattices, our analysis reveals a rich spectrum of states, from honeycomb patterns and ring structures to striped supersolids. By optimizing relevant parameters we show that transitions between distinct supersolids should be observable in current experiments.
Comments: | 8 pages, 8 figures |
Subjects: | Quantum Gases (cond-mat.quant-gas) |
Journal reference: | Phys. Rev. A 104, 013310 (2021) |
DOI: | 10.1103/PhysRevA.104.013310 |
Cite as: | arXiv:2103.12688 [cond-mat.quant-gas] |
(or arXiv:2103.12688v2 [cond-mat.quant-gas] for this version) |
In this review, we discuss the physical characteristics of the magnetic dual chiral density wave (MDCDW) phase of dense quark matter and argued why it is a promising candidate for the interior matter phase of neutron stars. The MDCDW condensate occurs in the presence of a magnetic field. It is a single-modulated chiral density wave characterized by two dynamically generated parameters: the fermion quasiparticle mass m and the condensate spatial modulation q. The lowest Landau level quasiparticle modes in the MDCDW system are asymmetric about the zero energy, a fact that leads to the topological properties and anomalous electric transport exhibited by this phase. The topology makes the MDCDW phase robust against thermal phonon fluctuations, and as such, it does not display the Landau-Peierls instability, a stapled feature of single-modulated inhomogeneous chiral condensates in three dimensions. The topology is also reflected in the presence of the electromagnetic chiral anomaly in the effective action and in the formation of hybridized propagating modes known as an axion-polaritons. Taking into account that one of the axion-polaritons of this quark phase is gapped, we argued how incident γ-ray photons can be converted into gapped axion-polaritons in the interior of a magnetar star in the MDCDW phase leading the star to collapse, a phenomenon that can serve to explain the so-called missing pulsar problem in the galactic center.
Subjects: | High Energy Physics - Phenomenology (hep-ph) |
Journal reference: | Universe 7 (2021) 12, 458 |
Cite as: | arXiv:2201.04032 [hep-ph] |
(or arXiv:2201.04032v1 [hep-ph] for this version) |
Hyperon (Y) mixing in neutron-star matter brings about a remarkable softening of the equation of state (EoS) and the maximum mass is reduced to a value far less than 2M⊙. One idea to avoid this "hyperon puzzle in neutron stars" is to assume that the many-body repulsions work universally for every kind of baryons. The other is to take into account the quark deconfinement phase transitions from a hadronic EoS to a sufficiently stiff quark-matter EoS. In the present approach, both effects are handled in a common framework. As well as the hadronic matter, the quark matter with the two-body quark-quark interactions are treated within the Brueckner-Bethe-Goldstone theory beyond the mean field frameworks, where interaction parameters are based on the terrestrial data. The derived mass-radius relations of neutron stars show that maximum masses reach over 2M⊙ even in the cases of including hadron-quark phase transitions, being consistent with the recent observations for maximum masses and radii of neutron stars by the NICER measurements and the other multimessenger data.
Subjects: | Nuclear Theory (nucl-th); High Energy Astrophysical Phenomena (astro-ph.HE) |
DOI: | 10.1103/PhysRevC.105.015804 |
Cite as: | arXiv:2112.12931 [nucl-th] |
(or arXiv:2112.12931v1 [nucl-th] for this version) |
Solitons in the extended hydrodynamic model of the dipolar Bose-Einstein condensate with quantum fluctuations are considered. This model includes the continuity equation for the scalar field of concentration, the Euler equation for the vector field of velocity, the pressure evolution equation for the second rank tensor of pressure, and the evolution equation for the third rank tensor. Large amplitude soliton solution caused by the dipolar part of quantum fluctuations is found. It appears as the bright soliton. Hence, it is the area of compression of the number of particles. Moreover, it exists for the repulsive short-range interaction.
Comments: | 9 pages, 4 figures |
Subjects: | Quantum Gases (cond-mat.quant-gas) |
DOI: | 10.1140/epjd/s10053-021-00071-1 |
Cite as: | arXiv:2009.12720 [cond-mat.quant-gas] |
(or arXiv:2009.12720v1 [cond-mat.quant-gas] for this version) |
Massive gravity theories have been developed as viable IR modifications of gravity motivated by dark energy and the problem of the cosmological constant. On the other hand, modified gravity and modified dark matter theories were developed with the aim of solving the problems of standard cold dark matter at galactic scales. Here we propose to adapt the framework of ghost-free massive bigravity theories to reformulate the problem of dark matter at galactic scales. We investigate a promising alternative to dark matter called dipolar dark matter (DDM) in which two different species of dark matter are separately coupled to the two metrics of bigravity and are linked together by an internal vector field. We show that this model successfully reproduces the phenomenology of dark matter at galactic scales (MOND) as a result of a mechanism of gravitational polarisation. The model is safe in the gravitational sector, but because of the particular couplings of the matter fields and vector field to the metrics, a ghost in the decoupling limit is present in the dark matter sector. However, it might be possible to push the mass of the ghost beyond the strong coupling scale by an appropriate choice of the parameters of the model. Crucial questions to address in future work are the exact mass of the ghost, and the cosmological implications of the model.
Comments: | 27 pages, journal version |
Subjects: | High Energy Physics - Theory (hep-th); Cosmology and Nongalactic Astrophysics (astro-ph.CO); General Relativity and Quantum Cosmology (gr-qc) |
DOI: | 10.1088/1475-7516/2015/12/026 |
Report number: | NORDITA-2015-57 |
Cite as: | arXiv:1505.05146 [hep-th] |
(or arXiv:1505.05146v2 [hep-th] for this version) |
We systematically investigate the ground state and elementary excitations of a Bose-Einstein Condensate with a synthetic vector potential, which is induced by the many-body effects and atom-light coupling. For a sufficiently strong inter-atom interaction, we find the condensate undergoes a Stoner-type ferromagnetic transition through the self-consistent coupling with the vector potential. For a weak interaction, the critical velocity of a supercurrent is found anisotropic due to the density fluctuations affecting the gauge field. We further analytically demonstrate the topological ground state with a coreless vortex ring in a 3D harmonic trap and a coreless vortex-antivortex pair in a 2D trap. The circulating persistent current is measurable in the time-of-flight experiment or in the dipolar oscillation through the violation of Kohn theorem.
Comments: | 5+3 pages of RevTex4-1, 4+1 figures |
Subjects: | Quantum Gases (cond-mat.quant-gas); Quantum Physics (quant-ph) |
Cite as: | arXiv:1411.5868 [cond-mat.quant-gas] |
(or arXiv:1411.5868v3 [cond-mat.quant-gas] for this version) | |
Journal reference: | Phys. Rev. A 92, 013604 (2015) |
Related DOI: | https://doi.org/10.1103/PhysRevA.92.013604 Focus to learn more |
Building upon the Noether charge formalism of Iyer and Wald, we derive a variational formula for spacetimes admitting a Killing vector field, for a generic energy-momentum distribution with compact support. Applying this general result to the particular case of a binary system of spinning compact objects moving along an exactly circular orbit, modelled using the multipolar gravitational skeleton formalism, we derive a first law of compact binary mechanics at dipolar order. We prove the equivalence of this new result with the canonical Hamiltonian first law previously derived for binary systems of spinning compact objects, for spins colinear with the orbital angular momentum. This paper paves the way to an extension of the first law of binary mechanics to the next quadrupolar order, thereby accounting for the spin-induced and tidally-induced deformability of the compact bodies.
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Comments: | 44 pages, 3 figures |
Subjects: | General Relativity and Quantum Cosmology (gr-qc) |
Cite as: | arXiv:2202.09345 [gr-qc] |
(or arXiv:2202.09345v1 [gr-qc] for this version) | |
https://doi.org/10.48550/arXiv.2202.09345 Focus to learn m |
We discuss a remarkable correspondence between the description of Black Holes as highly occupied condensates of N weakly interacting gravitons and that of Color Glass Condensates (CGCs) as highly occupied gluon states. In both cases, the dynamics of "wee partons" in Regge asymptotics is controlled by emergent semi-hard scales that lead to perturbative unitarization and classicalization of 2→N particle amplitudes at weak coupling. In particular, they attain a maximal entropy permitted by unitarity, bounded by the inverse coupling α of the respective constituents. Strikingly, this entropy is equal to the area measured in units of the Goldstone constant corresponding to the spontaneous breaking of Poincar{é} symmetry by the corresponding graviton or gluon condensate. In gravity, the Goldstone constant is the Planck scale, and gives rise to the Bekenstein-Hawking entropy. Likewise, in the CGC, the corresponding Goldstone scale is determined by the onset of gluon screening. We point to further similarities in Black Hole formation, thermalization and decay, to that of the Glasma matter formed from colliding CGCs in ultrarelativistic nuclear collisions, which decays into a Quark-Gluon Plasma.
Comments: | 20 pages; typos fixed, references added, small clarifications to text |
Subjects: | High Energy Physics - Theory (hep-th); General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Phenomenology (hep-ph); Nuclear Theory (nucl-th) |
Cite as: | arXiv:2106.11989 [hep-th] |
(or arXiv:2106.11989v2 [hep-th] for this version) | |
https://doi.org/10.48550/arXiv.2106.11989 Focus to learn more |
We analyze dynamics of chiral gauge theories based on the SU(N) gauge group with one anti-symmetric tensor A and (N−4) anti-fundamentals Fi when N is odd. Based on the continuity to the supersymmetric gauge theories with anomaly-mediated supersymmetry breaking, we claim that the global SU(N−4) symmetry is spontaneously broken to Sp(N−5). There are N−5 massless fermions as a fundamental representation of Sp(N−5), and another massless fermion, together saturating the anomaly matching conditions. When N is even, the unbroken flavor symmetry is Sp(N−4) while there are no massless fermions. Our result is different from the dynamics suggested by tumbling where the full SU(N−4) symmetry is unbroken, but the tumbling picture can be modified via the addition of a second condensate to produce the symmetry breaking pattern predicted from our method.
Subjects: | High Energy Physics - Theory (hep-th) |
Cite as: | arXiv:2104.10171 [hep-th] |
(or arXiv:2104.10171v2 [hep-th] for this version) | |
https://doi.org/10.48550/arXiv.2104.10171 Focus to learn more | |
Journal reference: | Phys. Rev. D 104, 065018 (2021) |
Related DOI: | https://doi.org/10.1103/PhysRevD.104.065018 Focus to learn more |