The interplay among the possible variation of gauge coupling and the inflationary dynamics is investigated in a simplified toy model. Depending upon various parameters (scalar mass, curvature scale at the end of inflation and at the onset of the radiation epoch), the two-point function of the magnetic inhomogeneities grows during the de Sitter stage of expansion and, consequently, large scale m...

We experimentally demonstrate collective strong coupling, optical bi-stability (OB) and all-optical switching in a system consisting of ultracold Rb atoms, trapped in a dark magneto-optical trap (DMOT), coupled to an optical Fabry-Perot cavity. The strong coupling is established by measuring the vacuum Rabi splitting (VRS) of a weak onaxis probe beam. The dependence of VRS on the probe beam pow...

We establish a nonminimal Einstein-Yang-Mills-Higgs model, which contains six coupling parameters. First three parameters relate to the nonminimal coupling of non-Abelian gauge field and gravity field, two parameters describe the so-called derivative nonminimal coupling of scalar multiplet with gravity field, and the sixth parameter introduces the standard coupling of scalar field with Ricci sc...

When an input Gaussian beam is improperly aligned and mode-matched to a stable optical resonator, the electric field in the resonator couples to off-axis spatial eigenmodes. We show that a translation of the input axis or a mismatch of the beam waist to the resonator waist size causes a coupling of off-axis modes which is inphase with the input field. On the other hand, a tilt of the input beam...

An optically thin MEMS beam suspended above a substrate and illuminated with a CW laser forms an interferometer, coupling out-of-plane deflection of the beam to absorption within it. In turn, laser absorption creates thermal stresses which drive further deflection. This coupling of motion to thermal stresses can cause limit cycle oscillations in which the beam vibrates in the absence of periodi...

We study the enhanced Kerr-nonlinear coefficient in a three-level A-type atomic system for various coupling-beam powers. The Kerr-nonlinear coefficient behaves very differently in the strong and the weak coupling power regions and changes sign when the coupling or probe frequency detuning changes sign. Comparisons of Kerr-nonlinear coefficients as functions of probe frequency detuning, coupling...

A theory of parametric amplification in a filamentary electron beam by transverse fields is developed in coupled mode form. Space charge effects are neglected. In addition to beam modes at the signal frequency, beam modes at frequencies wn=w+wv, n=O, ±1, ±2· ··,where wp is the pump frequency, are coupled together. A discussion of the general form of the equations is given and reveals the circum...

The LEDA RFQ is a 350-MHz continuous-wave (CW) radio-frequency quadrupole linac. LEDA is the low energy demonstration accelerator, a full power front-end prototype for the accelerator production of tritium (APT) linac. This machine has accelerated a 100-mA CW proton beam from 75 keV to 6.7 MeV. The 8-m-long RFQ accepts a dc, 75–keV, ~110-mA H beam from the LEDA injector, bunches the beam, and a...

We propose a device that can take an arbitrary monochromatic input beam and, automatically and without any calculations, couple it into a single-mode guide or beam. Simple feedback loops from detectors to modulator elements allow the device to adapt to any specific input beam form. Potential applications include automatic compensation for misalignment and defocusing of an input beam, coupling o...

Through the pseudo-static test on the steel truss coupling beams with buckling-restrained brace, the bearing capacity, deformation capacity, hysteresis curve, skeleton curve, ductility, Energy Dissipation and stiffness degradation of such coupling beam are understood. The test results show that the steel truss coupling beams with buckling-restrained brace is characterized by bigger bearing capa...