Entangling nanomechanical oscillators in a ring cavity by feeding squeezed light

A scheme is presented for entangling two separated nanomechanical oscillators by injecting broad band squeezed vacuum light and laser light into the ring cavity. We work in the resolved sideband regime. We find that in order to obtain the maximum entanglement of the two oscillators, the squeezing parameter of the input light should be about 1. We report significant entanglement over a very wide range of power levels of the pump and temperatures of the environment.Comment: 13 pages,5 figure

Reactive-Coupling-Induced Normal Mode Splittings in Microdisk Resonators Coupled to Waveguides

We study the optomechanical design introduced by M. Li et al. [Phys. Rev. Lett. {\bf 103}, 223901 (2009)], which is very effective for investigation of the effects of reactive coupling. We show the normal mode splitting which is due solely to reactive coupling rather than due to dispersive coupling. We suggest feeding the waveguide with a pump field along with a probe field and scanning the output probe for evidence of reactive-coupling-induced normal mode splitting.Comment: 4 pages,6 figure

Spontaneous spatial fractal pattern formation in absorptive systems

We predict, for the first time to our knowledge, that purely-absorptive nonlinearity can support spontaneous spatial fractal pattern formation. A passive optical ring cavity with a thin slice of saturable absorber is analyzed. Linear stability analysis yields threshold curves for Turing (static) instabilities with features proposed as characteristics of potential fractal pattern formation. Numerical simulations of the fully-nonlinear dynamics, with both one and two transverse dimensions, confirm theoretical predictions

Weak gravity conjecture constraints on inflation

We consider the gravitational correction to the coupling of the scalar fields. Weak gravity conjecture says that the gravitational correction to the running of scalar coupling should be less than the contribution from scalar fields. For instance, a new scale $\Lambda=\lambda_4^{1/2}M_p$ sets a UV cutoff on the validity of the effective $\lambda_4 \phi^4$ theory. Furthermore, this conjecture implies a possible constraint on the inflation model, e.g. the chaotic inflation model might be in the swampland.Comment: 11 pages, 3 figs; monor corrections; some clarifying remarks added and the final version for publication in JHE

Direct Evidence from Spitzer for a low-luminosity AGN at the center of the Elliptical Galaxy NGC 315

We present the {\it Spitzer} Space Telescope InfraRed Array Camera (IRAC) and Multiband Imaging Photometer (MIPS) observations of the elliptical galaxy NGC 315. After removal of the host galaxy's stellar emission, we detected for the first time an infrared-red nucleus in NGC 315. We measured the spectral energy distribution (SED) for this active nucleus with wavelength range covering from radio to X-ray, and obtained the bolometric luminosity of $\rm L_{bol} \approx 1.9 \times 10^{43} ergs s^{-1}$, corresponding to an extremely low Eddington ratio (L/L$_{\rm Edd}$) of 4.97 $\times$ 10$^{-4}$. Our results confirm that the physical nature of the nucleus of NGC 315 is a low-luminosity AGN, consistent with the recent optical and {\it Chandra} X-ray observations.Comment: 4 pages, accepted for publication in ApJ Letter