ترغب بنشر مسار تعليمي؟ اضغط هنا

In this note we state (with minor corrections) and give an alternative proof of a very general hypergeometric transformation formula due to Slater. As an application, we obtain a new hypergeometric transformation formula for a ${}_5F_4(-1)$ series wi th one pair of parameters differing by unity expressed as a linear combination of two ${}_3F_2(1)$ series.
79 - Y. S. Kim 2014
It is noted that the Poincare sphere for polarization optics contains the symmetries of the Lorentz group. The sphere is thus capable of describing the internal space-time symmetries dictated by Wigners little groups. For massive particles, the littl e group is like the three-dimensional rotation group, while it is like the two-dimensional Euclidean group for massless particles. It is shown that the Poincare sphere, in addition, has a symmetry parameter corresponding to reducing the particle mass from a positive value to zero. The Poincare sphere thus the gives one unified picture of Wigners little groups for massive and massless particles.
The aim in this note is to provide a generalization of an interesting entry in Ramanujans Notebooks that relate sums involving the derivatives of a function Phi(t) evaluated at 0 and 1. The generalization obtained is derived with the help of expressi ons for the sum of terminating 3F2 hypergeometric functions of argument equal to 2, recently obtained in Kim et al. [Two results for the terminating 3F2(2) with applications, Bull. Korean Math. Soc. 49 (2012) pp. 621{633]. Several special cases are given. In addition we generalize a summation formula to include integral parameter differences.
Expressions for the summation of a new series involving the Laguerre polynomials are obtained in terms of generalized hypergeometric functions. These results provide alternative, and in some cases simpler, expressions to those recently obtained in the literature.
We present a moment expansion method for the systematic characterization of the polarization properties of quantum states of light. Specifically, we link the method to the measurements of the Stokes operator in different directions on the Poincar{e} sphere, and provide a method of polarization tomography without resorting to full state tomography. We apply these ideas to the experimental first- and second-order polarization characterization of some two-photon quantum states. In addition, we show that there are classes of states whose polarization characteristics are dominated not by their first-order moments (i.e., the Stokes vector) but by higher-order polarization moments.
42 - Y. S. Kim 2008
One hundred years ago, in 1908, Hermann Minkowski completed his proof that Maxwells equations are covariant under Lorentz transformations. During this process, he introduced a four-dimensional space called the Minkowskian space. In 1949, P. A. M. Dir ac showed the Minkowskian space can be handled with the light-cone coordinate system with squeeze transformations. While the squeeze is one of the fundamental mathematical operations in optical sciences, it could serve useful purposes in two-level systems. Some possibilities are considered in this report. It is shown possible to cross the light-cone boundary in optical and two-level systems while it is not possible in Einsteins theory of relativity.
121 - S. Baskal , Y. S. Kim 2008
The beam transfer matrix, often called the $ABCD$ matrix, is a two-by-two matrix with unit determinant, and with three independent parameters. It is noted that this matrix cannot always be diagonalized. It can however be brought by rotation to a matr ix with equal diagonal elements. This equi-diagonal matrix can then be squeeze-transformed to a rotation, to a squeeze, or to one of the two shear matrices. It is noted that these one-parameter matrices constitute the basic elements of the Wigners little group for space-time symmetries of elementary particles. Thus every $ABCD$ matrix can be written as a similarity transformation of one of the Wigner matrices, while the transformation matrix is a rotation preceded by a squeeze. This mathematical property enables us to compute scattering processes in periodic systems. Laser cavities and multilayer optics are discussed in detail. For both cases, it is shown possible to write the one-cycle transfer matrix as a similarity transformation of one of the Wigner matrices. It is thus possible to calculate the $ABCD$ matrix for an arbitrary number of cycles.
We investigated the inhomogeneous electronic properties at the surface and interior of VO_{2} thin films that exhibit a strong first-order metal-insulator transition (MIT). Using the crystal structural change that accompanies a VO_{2} MIT, we used bu lk-sensitive X-ray diffraction (XRD) measurements to estimate the fraction of metallic volume p^{XRD} in our VO_{2} film. The temperature dependence of the p$^{XRD}$ was very closely correlated with the dc conductivity near the MIT temperature, and fit the percolation theory predictions quite well: $sigma$ $sim$ (p - p_{c})^{t} with t = 2.0$pm$0.1 and p_{c} = 0.16$pm$0.01. This agreement demonstrates that in our VO$_{2}$ thin film, the MIT should occur during the percolation process. We also used surface-sensitive scanning tunneling spectroscopy (STS) to investigate the microscopic evolution of the MIT near the surface. Similar to the XRD results, STS maps revealed a systematic decrease in the metallic phase as temperature decreased. However, this rate of change was much slower than the rate observed with XRD, indicating that the electronic inhomogeneity near the surface differs greatly from that inside the film. We investigated several possible origins of this discrepancy, and postulated that the variety in the strain states near the surface plays an important role in the broad MIT observed using STS. We also explored the possible involvement of such strain effects in other correlated electron oxide systems with strong electron-lattice interactions.
mircosoft-partner

هل ترغب بارسال اشعارات عن اخر التحديثات في شمرا-اكاديميا