Current algebra based effective chiral theory of mesons and a new EW theory

A current algebra based effective chiral theory of pseudoscalar, vector, axial-vector mesons is reviewed. A new mechanism generating the masses and guage fixing terms of gauge boson is revealed from this effective theory. A EW theory without Higgs is proposed. The masses and gauge fixing terms of W and Z are dynamically generated. Three heavy scalar fields are dynamically generated too. They are ghosts.Comment: 4 pages, talk presented at conference of QCD and hadronic physics, 6/16-6/21, Beijing, Chin

On the afterglow and progenitor of FRB 150418

Keane et al. recently detected a fading radio source following FRB 150418, leading to the identification of a putative host galaxy at $z = 0.492 \pm 0.008$. Assuming that the fading source is the afterglow of FRB 150418, I model the afterglow and constrain the isotropic energy of the explosion to be a few $10^{50}$ erg, comparable to that of a short duration GRB. The outflow may have a jet opening angle of $\sim 0.22$ rad, so that the beaming-corrected energy is below $10^{49}$ erg. The results rule out most FRB progenitor models for this FRB, but may be consistent with either of the following two scenarios. The first scenario invokes a merger of an NS-NS binary, which produced an undetected short GRB and a supra-massive neutron star, which subsequently collapsed into a black hole, probably 100s of seconds after the short GRB. The second scenario invokes a merger of a compact star binary (BH-BH, NS-NS, or BH-NS) system whose pre-merger dynamical magnetospheric activities made the FRB, which is followed by an undetected short GRB-like transient. The gravitational wave (GW) event GW150914 would be a sister of FRB 150418 in this second scenario. In both cases, one expects an exciting prospect of GW/FRB/GRB associations.Comment: ApJL, in pres

Mergers of Charged Black Holes: Gravitational Wave Events, Short Gamma-Ray Bursts, and Fast Radio Bursts

The discoveries of GW 150914, GW 151226, and LVT 151012 suggest that double black hole (BH-BH) mergers are common in the universe. If at least one of the two merging black holes carries certain amount of charge, possibly retained by a rotating magnetosphere, the inspiral of a BH-BH system would drive a global magnetic dipole normal to the orbital plane. The rapidly evolving magnetic moment during the merging process would drive a Poynting flux with an increasing wind power. The magnetospheric activities during the final phase of the merger would make a fast radio burst (FRB) if the BH charge can be as large as a factor of $\hat q \sim (10^{-9}-10^{-8})$ of the critical charge $Q_c$ of the BH. At large radii, dissipation of the Poynting flux energy in the outflow would power a short duration high-energy transient, which would appear as a detectable short-duration gamma-ray burst (GRB) if the charge can be as large as $\hat q \sim (10^{-5}-10^{-4})$. The putative short GRB coincident with GW 150914 recorded by Fermi GBM may be interpreted with this model. Future joint GW/GRB/FRB searches would lead to a measurement or place a constraint on the charges carried by isolate black holes.Comment: 5 pages, more discussion on BH electrodynamics and origin of BH charge, final version to appear in ApJ

The Delay Time of Gravitational Wave — Gamma-Ray Burst Associations

The first gravitational wave (GW) — gamma-ray burst (GRB) association, GW170817/GRB 170817A, had an offset in time, with the GRB trigger time delayed by ∼1.7 s with respect to the merger time of the GW signal. We generally discuss the astrophysical origin of the delay time, Δt, of GW-GRB associations within the context of compact binary coalescence (CBC) — short GRB (sGRB) associations and GW burst — long GRB (lGRB) associations. In general, the delay time should include three terms, the time to launch a clean (relativistic) jet, Δtjet; the time for the jet to break out from the surrounding medium, Δtbo; and the time for the jet to reach the energy dissipation and GRB emission site, ΔtGRB. For CBC-sGRB associations, Δtjet and Δtbo are correlated, and the final delay can be from 10 ms to a few seconds. For GWB-lGRB associations, Δtjet and Δtbo are independent. The latter is at least ∼10 s, so that Δt of these associations is at least this long. For certain jet launching mechanisms of lGRBs, Δt can be minutes or even hours long due to the extended engine waiting time to launch a jet. We discuss the cases of GW170817/GRB 170817A and GW150914/GW150914-GBM within this theoretical framework and suggest that the delay times of future GW/GRB associations will shed light into the jet launching mechanisms of GRBs

FRB 121102: A Repeatedly Combed Neutron Star by a Nearby Low-luminosity Accreting Supermassive Black Hole

The origin of fast radio bursts (FRBs) remains mysterious. Recently, the only repeating FRB source, FRB 121102, was reported to possess an extremely large and variable rotation measure (RM). The inferred magnetic field strength in the burst environment is comparable to that in the vicinity of the supermassive black hole Sagittarius A* of our Galaxy. Here, we show that all of the observational properties of FRB 121102 (including the high RM and its evolution, the high linear polarization degree, an invariant polarization angle across each burst and other properties previously known) can be interpreted within the cosmic comb model, which invokes a neutron star with typical spin and magnetic field parameters whose magnetosphere is repeatedly and marginally combed by a variable outflow from a nearby low-luminosity accreting supermassive black hole in the host galaxy. We propose three falsifiable predictions (periodic on/off states, and periodic/correlated variation of RM and polarization angle) of the model and discuss other FRBs within the context of the cosmic comb model as well as the challenges encountered by other repeating FRB models in light of the new observations