Spinor model of a perfect fluid

Different characteristic of matter influencing the evolution of the Universe has been simulated by means of a nonlinear spinor field. We have considered two cases where the spinor field nonlinearity occurs either as a result of self-action or due to the interaction with a scalar field.Comment: 5 pages, some misprints are corrected, some new expressions are adde

Nonlinear Spinor Fields and its role in Cosmology

Different characteristic of matter influencing the evolution of the Universe has been simulated by means of a nonlinear spinor field. Exploiting the spinor description of perfect fluid and dark energy evolution of the Universe given by an anisotropic Bianchi type-VI, VI$_0$, V, III, I or isotropic Friedmann-Robertson-Walker (FRW) one has been studied. It is shown that due to some restrictions on metric functions, initial anisotropy in the models Bianchi type-VI, VI$_0$, V and III does not die away, while the anisotropic Bianchi type-I models evolves into the isotropic one.Comment: 22 pages, 12 Figure

Interacting scalar and spinor fields in Bianchi type I universe filled with magneto-fluid

Self-consistent system of spinor, scalar and BI gravitational fields in presence of magneto-fluid and $\Lambda$-term is considered. Assuming that the expansion of the BI universe is proportional to the $\sigma_1^1$ component of the shear tensor, exact solutions for the metric functions, as well as for scalar and spinor fields are obtained. For a non-positive $\Lambda$ the initially anisotropic space-time becomes isotropic one in the process of expansion, whereas, for $\Lambda > 0$ an oscillatory mode of expansion of the BI model occurs.Comment: RevTex4, 8 pages, no figure

Application of terahertz spectroscopy to the characterization of biological samples using birefringence silicon grating

We present a device and method for performing vector transmission spectroscopy on biological specimens at terahertz (THz) frequencies. The device consists of artificial dielectric birefringence obtained from silicon microfluidic grating structures. The device can measure the complex dielectric function of a liquid, across a wide THz band of 2 to 5.5 THz, using a Fourier transform infrared spectrometer. Measurement data from a range of liquid specimens, including sucrose, salmon deoxyribonucleic acid (DNA), herring DNA, and bovine serum albumin protein solution in water are presented. The specimen handling is simple, using a microfluidic channel. The transmission through the device is improved significantly and thus the measurement accuracy and bandwidth are increase

Noncommutative quantum mechanics of a harmonic oscillator under linearized gravitational waves

We consider the quantum dynamics of a harmonic oscillator in noncommutative space under the influence of linearized gravitational waves (GW) in the long wave-length and low-velocity limit. Following the prescription in \cite{ncgw1} we quantize the system. The Hamiltonian of the system is solved by using standard algebraic iterative methods. The solution shows signatures of the coordinate noncommutativity via alterations in the oscillation frequency of the harmonic oscillator system from its commutative counterpart. Moreover, it is found that the response of the harmonic oscillator to periodic GW, when their frequencies match, will oscillate with a time scale imposed by the NC parameter. We expect this noncommutative signature to show up as some noise source in the GW detection experiments since the recent phenomenological upper-bounds set on spatial noncommutative parameter implies a length-scale comparable to the length-variations due to the passage of gravitational waves, detectable in the present day GW detectors.Comment: 6 pages Late