118895124
Line-broadening in gravitational radiation from gamma-ray burst-supernovae
Core-collapse in massive stars is believed to produce a rapidly spinning black hole surrounded by a compact disk or torus. This forms an energetic MeV-nucleus inside a remnant He-core, powered by black hole-spin energy. The output produces a GRB-supernova, while most of the energy released is in gravitational radiation. The intrinsic gravitational-wave spectrum is determined by multipole mass-moments in the torus. Quadrupole gravitational radiation is radiated at about twice the Keplerian frequency of the torus, which is non-axisymmetric when sufficiently slender, representing a ``{\em black hole-blob}" binary system or a "{\em blob-blob}" binary bound to the central black hole. We here discuss line-broadening in the observed spectrum due to Lense-Thirring precession, which modulates the orientation of the torus to the line-of-sight. This spectral feature is long-lived, due to weak damping of precessional motion. These events are believed to occur perhaps once per year within a distance of 100Mpc, which provides a candidate source for Advanced LIGO.
16162020
Boson Stars with Self-Interacting Quantum Scalar Fields
The Klein-Gordon-Einstein equations of classical real scalar fields have time-dependent solutions (periodic in time). We show that quantum real scalar fields can form non-oscillating (static) solitonic objects, which are quite similar to the solutions describing boson stars formed with classical and quantum complex scalar fields (the latter will be studied in this paper). We numerically analyze the difference between them concerning the mass of boson stars. On the other hand, we suggest an interesting test (a viable process that the boson star may undergo in the early universe) for the formation of boson stars. That is, it is questioned that after a second-order phase transition (a simple toy model will be considered here), what is the fate of the boson star composed of quantum real scalar field.
5695541
Nonvanishing magnetic flux through the slightly charged Kerr black hole
In association with the Blanford-Znajek mechanism for rotational energy extraction from Kerr black holes, it is of some interest to explore how much of magnetic flux can actually penetrate the horizon at least in idealized situations. For completely uncharged Kerr hole case, it has been known for some time that the magnetic flux gets entirely expelled when the hole is maximally-rotating. In the mean time, it is known that when the rotating hole is immersed in an originally uniform magnetic field surrounded by an ionized interstellar medium (plasma), which is a more realistic situation, the hole accretes certain amount of electric charge. In the present work, it is demonstrated that as a result of this accretion charge small enough not to disturb the geometry, the magnetic flux through this slightly charged Kerr hole depends not only on the hole's angular momentum but on the hole's charge as well such that it never vanishes for any value of the hole's angular momentum.
118626590
Instanton solutions mediating tunneling between the degenerate vacua in curved space
We investigate the instanton solution between the degenerate vacua in curved space. We show that there exist $O(4)$-symmetric solutions not only in de Sitter but also in both flat and anti\char21{}de Sitter space. The geometry of the new type of solutions is finite and preserves the ${Z}_{2}$ symmetry. The nontrivial solution corresponding to the tunneling is possible only if gravity is taken into account. The numerical solutions as well as the analytic computations using the thin-wall approximation are presented. We expect that these solutions do not have any negative mode as in the instanton solution.
2929156
Relativistic Electrodynamics of Spinning Compact Objects
A theoretical study of some electrodynamic features of a region close to a slowly-rotating magnetized relativistic star is performed. To be a little more specific, based on the solution-generating method given by Wald, the magnetic fields around both uncharged and (slightly) charged relativistic stars have been obtained. Particularly for a charged relativistic star, again following the argument by Wald, the star was shown to gradually accrete charge until it reached an equilibrium value Q = 2B0J . This value of the equilibrium charge seems to be generic as a rotating black hole is known to accrete exactly the same amount. Although these results are equally relevant to all species of slowly-rotating relativistic stars, we particularly have the rotating neutron star in mind. As such, it would be of some interest to attempt to make contact with a real pulsar case. Thus, we discuss how many of the theoretical results obtained in the present work can be carried over to a realistic, general relativistic description of a pulsar’s magnetosphere.
118417575
Cosmic Background Anisotropy due to Neutrino Oscillations Revisited
This paper has been withdrawn by the author due to a crucial error in several equations.
14255357
Closed strings interacting with non-commutative D-branes
Abstract Closed string dynamics in the presence of non-commutative D p -branes is investigated. In particular, we compute bulk closed string two-point scattering amplitudes; the bulk space-time geometries encoded in the amplitudes are shown to be consistent with the recently proposed background space-time geometries dual to non-commutative Yang–Mills theories. Three-point closed string absorption/emission amplitudes are obtained to show some features of non-commutative D p -branes, such as modified pole structures and exponential phase factors linearly proportional to the external closed string momentum.
119269079
Double non-global logarithms in-n-out of jets
A bstractWe derive the leading non-global logarithms (NGLs) of ratios of jet masses m1,2 and a jet energy veto Λ due to soft gluons splitting into regions in and out of jets. Such NGLs appear in any exclusive jet cross section with multiple jet measurements or with a veto imposed on additional jets. Here, we consider back-to-back jets of radius R produced in e+e− collisions, found with a cone or recombination algorithm. The leading NGLs are of the form $\alpha_{\text{s}}^2{\text{l}}{{\text{n}}^2}(\Lambda /{m_{{1},{2}}})$ or $\alpha_{\text{s}}^2{\text{l}}{{\text{n}}^2}({m_1}/{m_2})$. Their coefficients depend both on the algorithm and on R. We consider cone, kT, anti-kT, and Cambridge-Aachen algorithms. In addition to determining the full algorithmic and R dependence of the leading NGLs, we derive new relations among their coefficients. We also derive to all orders in αs a factorized form for the soft function S(kL, kR, Λ) in the cross section σ(m1, m2, Λ) in which dependence on each of the global logs of μ/kL, μ/kR and μ/Λ determined by the renormalization group are separated from one another and from the non-global logs. The same kind of soft function, its associated non-global structure, and the algorithmic dependence we derive here will also arise in exclusive jet cross sections at hadron colliders, and must be understood and brought under control to achieve precise theoretical predictions.
117935318
CP‐Violating Sources for Electroweak Baryogenesis
In this talk I derive the CP‐violating sources for the squark number density in the MSSM generated by interactions with the spacetime‐varying Higgs vev during a first‐order electroweak phase transition.
122534296
Peeking inside jets for clues of new physics
Observables probing jet structure and substructure help uncover clues about the energetic particles which originated them, such as ordinary light quarks and gluons or from decays of heavy particles in and beyond the Standard Model. This talk overviews such recently introduced methods.
119244769
Solutions in IR Modified Horava-Lifshitz Gravity
In order to allow the asymptotically flat, we consider Ho\v{r}ava-Lifshitz gravity theory with a soft violation of the detailed balance condition and obtain various solutions. In particular, we find that such theory coupled to a global monopole leads to a solution representing a space with deficit solid angle, which is well matched with genuine feature of GR.