A Population of Short-Period Variable Quasars from PTF as Supermassive Black Hole Binary Candidates

Supermassive black hole binaries (SMBHBs) at sub-parsec separations should be common in galactic nuclei, as a result of frequent galaxy mergers. Hydrodynamical simulations of circumbinary discs predict strong periodic modulation of the mass accretion rate on time-scales comparable to the orbital period of the binary. As a result, SMBHBs may be recognized by the periodic modulation of their brightness. We conducted a statistical search for periodic variability in a sample of 35,383 spectroscopically confirmed quasars in the photometric database of the Palomar Transient Factory (PTF). We analysed Lomb-Scargle periodograms and assessed the significance of our findings by modeling each individual quasar's variability as a damped random walk (DRW). We identified 50 quasars with significant periodicity beyond the DRW model, typically with short periods of a few hundred days. We find 33 of these to remain significant after a re-analysis of their periodograms including additional optical data from the intermediate-PTF and the Catalina Real-Time Transient Survey (CRTS). Assuming that the observed periods correspond to the redshifted orbital periods of SMBHBs, we conclude that our findings are consistent with a population of unequal-mass SMBHBs, with a typical mass ratio as low as q = M2/M1 ~ 0.01.Comment: MNRAS (accepted), new section 4.

Neurino Cadence of TXS~0506+056 Consistent with Supermassive Binary Origin

On September 18, 2022, an alert by ceCube indicated that a ~170TeV neutrino arrived in directional coincidence with the blazar TXS 0506+056. This event adds to two previous ones: a neutrino alert from its direction on September 22, 2017, and a 3sigma signature of a dozen neutrinos in 2014/2015. deBruijn 2020 showed that these two previous neutrino emission episodes could be due to a supermassive binary black hole (SMBBH) where jet precession close to final coalescence results in periodic emission. This model predicted a new emission episode consistent with the September 18, 2022 neutrino observation. Here, we show that the neutrino cadence of TXS 0506+056 is consistent with a SMBBH origin with mass ratios q3e8Msun. For the first time, we calculate the characteristic strain of the gravitational wave emission of the binary, and show that the merger could be detectable by LISA for black hole masses <5e8Msun if the mass ratios are in the range 0.1<q<0.3. We predict that there can be a neutrino flare existing in the still to be analyzed IceCube data peaking some time between 08/2019 and 01/2021 if a precessing jet is responsible for all three detected emission episodes. The next flare is expected to peak in the period 01/2023 to 08/2026. Further observation will make it possible to constrain the mass ratio as a function of the black hole mass more precisely and would open the window toward the preparation of the detection of SMBBH mergers.Comment: 10 pages, 2 figures, submitte

Bremsstrahlung photon polarization for ee±→(eγ)e±ee^\pm\to (e\gamma)e^\pm, and ep→(eγ)pep\to (e\gamma)p high energy collisions

The polarization of bremsstrahlung photon in the processes $ee^\pm\to (e\gamma)e^\pm$, and $ep\to (e\gamma)p$ is calculated for peripheral kinematics, in the high energy limit where the cross section does not decrease with the incident energy. When the initial electron is unpolarized(longitudinally polarized) the final photon can be linearly (circularly) polarized. The Stokes parameters of the photon polarization are calculated as a function of the kinematical variables of process: the energy of recoil particle, the energy fraction of scattered electron, and the polar and azimuthal angles of photon. Numerical results are given in form of tables, for typical values of the relevant kinematic variables.Comment: 9 pages, 3 figure

Contributions of semi-hadronic states Pγ;Sγ,π+π−γP\gamma;S\gamma, \pi^+\pi^-\gamma to amm of muon, in frames of Nambu-Jona-Lasinio model

We calculate the contribution of semi-hadronic states with pseudoscalar $P=\pi^0, \eta$ and scalar ($\sigma$(550))meson accompanied with real photon as an intermediate state of a heavy photon to the anomalous magnetic moment of muon. We consider the intermediate states with $\pi_0$ and $\sigma$ as a hadrons in frames of Nambu-Jona-Lasinio model. The contribution of $\pi_0\gamma$ state is in agreement with results obtained in previous theoretical considerations as well as with experimental data $a_\mu^{\pi_0\gamma}\approx 4.5 \times 10^{-10}$, besides we estimate $a_{\mu}^{\eta\gamma}=0.7 \times 10^{-10}, a_{\mu}^{\sigma\gamma} \sim 1.5 \times 10^{-11}, a_{\mu}^{\pi^+\pi^-\gamma} \sim 3.2 \times 10^{-10}.$ We discass as well the LbL mechanism with $a_{\mu}^{lbl}=10.5 \cdot 10^{-10}.$Comment: 6 pages, 2 figure

Effects of Vacuum Polarization in Strong Magnetic Fields with an Allowance Made for the Anomalous Magnetic Moments of Particles

Given the anomalous magnetic moments of electrons and positrons in the one-loop approximation, we calculate the exact Lagrangian of an intense constant magnetic field that replaces the Heisenberg-Euler Lagrangian in traditional quantum electrodynamics (QED). We have established that the derived generalization of the Lagrangian is real for arbitrary magnetic fields. In a weak field, the calculated Lagrangian matches the standard Heisenberg-Euler formula. In extremely strong fields, the field dependence of the Lagrangian completely disappears, and the Lagrangian tends to a constant determined by the anomalous magnetic moments of the particles.Comment: 19 pages, 3 figure

Characterization of the seismic environment at the Sanford Underground Laboratory, South Dakota

An array of seismometers is being developed at the Sanford Underground Laboratory, the former Homestake mine, in South Dakota to study the properties of underground seismic fields and Newtonian noise, and to investigate the possible advantages of constructing a third-generation gravitational-wave detector underground. Seismic data were analyzed to characterize seismic noise and disturbances. External databases were used to identify sources of seismic waves: ocean-wave data to identify sources of oceanic microseisms, and surface wind-speed data to investigate correlations with seismic motion as a function of depth. In addition, sources of events contributing to the spectrum at higher frequencies are characterized by studying the variation of event rates over the course of a day. Long-term observations of spectral variations provide further insight into the nature of seismic sources. Seismic spectra at three different depths are compared, establishing the 4100-ft level as a world-class low seismic-noise environment.Comment: 29 pages, 16 figure

Reassessing candidate eccentric binary black holes: Results with a model including higher-order modes

The detection of eccentricity from a gravitational wave signal is expected to help distinguish between formation channels for a given binary. In this study, we reassess all previously-reported binary black holes with previous claims of possible eccentricity as well as a few binaries with more interesting source parameters, for the first time using a model (TEOBResumSGeneral) which accounts for the full eccentricity range possible and incorporates higher-order gravitational emission critical to model emission from highly eccentric orbits. We estimate the eccentricity of these five events. For the first time, we present marginal evidence of eccentricity for one of the events: GW190929. Contrary to previous work with different settings, we do not find evidence supporting eccentric orbits for the same systems. We find the incorporation of eccentricity in our analyses dramatically shifts the posterior in multiple parameters for several events, features could negatively impact other analyses

Dynamical principles in neuroscience

Dynamical modeling of neural systems and brain functions has a history of success over the last half century. This includes, for example, the explanation and prediction of some features of neural rhythmic behaviors. Many interesting dynamical models of learning and memory based on physiological experiments have been suggested over the last two decades. Dynamical models even of consciousness now exist. Usually these models and results are based on traditional approaches and paradigms of nonlinear dynamics including dynamical chaos. Neural systems are, however, an unusual subject for nonlinear dynamics for several reasons: (i) Even the simplest neural network, with only a few neurons and synaptic connections, has an enormous number of variables and control parameters. These make neural systems adaptive and flexible, and are critical to their biological function. (ii) In contrast to traditional physical systems described by well-known basic principles, first principles governing the dynamics of neural systems are unknown. (iii) Many different neural systems exhibit similar dynamics despite having different architectures and different levels of complexity. (iv) The network architecture and connection strengths are usually not known in detail and therefore the dynamical analysis must, in some sense, be probabilistic. (v) Since nervous systems are able to organize behavior based on sensory inputs, the dynamical modeling of these systems has to explain the transformation of temporal information into combinatorial or combinatorial-temporal codes, and vice versa, for memory and recognition. In this review these problems are discussed in the context of addressing the stimulating questions: What can neuroscience learn from nonlinear dynamics, and what can nonlinear dynamics learn from neuroscience?This work was supported by NSF Grant No. NSF/EIA-0130708, and Grant No. PHY 0414174; NIH Grant No. 1 R01 NS50945 and Grant No. NS40110; MEC BFI2003-07276, and Fundación BBVA

Veterinary use of thermal water and mud from Lake Hévíz for equestrian injury prevention and rehabilitation

Beneficial effects of thermal mud treatment in the human medical field have been known for many years. However, such treatments have never been studied and used in veterinary science. The aim of our study was to investigate how a mud treatment from Héviz Spa Lake affects the movement quality and flexibility of certain joints in horses. Wet sludge was applied on the knee, hock, elbow, shoulder, back, stifle, front and hind cannons and fetlock joints for a period of eight weeks. Our results show, that the mud treatment from Lake Héviz may have beneficial effects on the joints, and play an important role in the locomotion of horses