Calculation of Relativistic Nucleon-Nucleon Potentials in Three-Dimensions

In this paper, we have applied a three-dimensional approach for calculation of the relativistic nucleon-nucleon potential. The quadratic operator relation between the non-relativistic and the relativistic nucleon-nucleon interactions is formulated as a function of relative two-nucleon momentum vectors, which leads to a three-dimensional integral equation. The integral equation is solved by the iteration method, and the matrix elements of the relativistic potential are calculated from non-relativistic ones. Spin-independent Malfliet-Tjon potential is employed in the numerical calculations, and the numerical tests indicate that the two-nucleon observables calculated by the relativistic potential are preserved with high accuracy

Tiling Spaces are Inverse Limits

Let M be an arbitrary Riemannian homogeneous space, and let Omega be a space of tilings of M, with finite local complexity (relative to some symmetry group Gamma) and closed in the natural topology. Then Omega is the inverse limit of a sequence of compact finite-dimensional branched manifolds. The branched manifolds are (finite) unions of cells, constructed from the tiles themselves and the group Gamma. This result extends previous results of Anderson and Putnam, of Ormes, Radin and Sadun, of Bellissard, Benedetti and Gambaudo, and of G\"ahler. In particular, the construction in this paper is a natural generalization of G\"ahler's.Comment: Latex, 6 pages, including one embedded figur

KESAN PEMBANGUNAN KAWASAN PERINDUSTRIAN TERHADAP KOMUNITI PESISIR PANTAI DI PASIR GUDANG, JOHOR

Kawasan perindustrian Pasir Gudang merupakan sebuah kawasan perindustrian yang sedang giat membangun di Johor. Kawasan perindustrian Pasir Gudang dahulunya merupakan sebuah kawasan pedalaman yang hasil ekonominya bergantung kepada komoditi getah. Kini, pembangunan dalam sektor perindustrian telah membawa kepada pertambahan peluang pekerjaan dan pertumbuhan penduduk yang pesat. Hal ini secara langsung telah memberi kesan ke atas taraf hidup dan keadaan sosioekonomi masyarakat setempat khususnya terhadap komuniti pesisir pantai di kawasan Pasir Gudang. Meskipun pembangunan kawasan perindustrian rancak berlaku di sekeliling mereka, namun masih terdapat perkampungan di kawasan pesisir pantai yang masih mengekalkan nilai, tradisi dan amalan ekonomi masyarakat desa. Sehubungan dengan itu, kajian ini dijalankan bertujuan untuk menilai kesan pembangunan kawasan perindustrian terhadap tahap sosioekonomi komuniti pesisir pantai di kawasan Pasir Gudang. Kajian ini dijalankan dengan menggunakan kaedah kuantitatif deskriptif melibatkan seramai 60 orang ketua isi rumah yang terdiri daripada komuniti pesisir pantai di Kampung Tanjung Langsat dan Kampung Perigi Acheh. Hasil kajian ini mendapati terdapat perubahan yang ketara ke atas status sosioekonomi komuniti pesisir pantai akibat pembangunan kawasan perindustrian di Pasir Gudang. Antara perubahan positif yang diterima adalah dari aspek pekerjaan dan pendapatan. Manakala kesan negatif akibat pembangunan pesat kawasan perindustrian adalah dari aspek kesejahteraan sosial dan persekitaran

Crystalline ground states for classical particles

Pair interactions whose Fourier transform is nonnegative and vanishes above a wave number K_0 are shown to give rise to periodic and aperiodic infinite volume ground state configurations (GSCs) in any dimension d. A typical three dimensional example is an interaction of asymptotic form cos(K_0 r)/r^4. The result is obtained for densities rho >= rho_d where rho_1=K_0/2pi, rho_2=(sqrt{3}/8)(K_0/pi)^2 and rho_3=(1/8sqrt{2})(K_0/pi)^3. At rho_d there is a unique periodic GSC which is the uniform chain, the triangular lattice and the bcc lattice for d=1,2,3, respectively. For rho>rho_d the GSC is nonunique and the degeneracy is continuous: Any periodic configuration of density rho with all reciprocal lattice vectors not smaller than K_0, and any union of such configurations, is a GSC. The fcc lattice is a GSC only for rho>=(1/6 sqrt{3})(K_0/pi)^3.Comment: final versio

Extinctions and Correlations for Uniformly Discrete Point Processes with Pure Point Dynamical Spectra

The paper investigates how correlations can completely specify a uniformly discrete point process. The setting is that of uniformly discrete point sets in real space for which the corresponding dynamical hull is ergodic. The first result is that all of the essential physical information in such a system is derivable from its $n$-point correlations, $n= 2, 3, >...$. If the system is pure point diffractive an upper bound on the number of correlations required can be derived from the cycle structure of a graph formed from the dynamical and Bragg spectra. In particular, if the diffraction has no extinctions, then the 2 and 3 point correlations contain all the relevant information.Comment: 16 page

Modelling quasicrystals at positive temperature

We consider a two-dimensional lattice model of equilibrium statistical mechanics, using nearest neighbor interactions based on the matching conditions for an aperiodic set of 16 Wang tiles. This model has uncountably many ground state configurations, all of which are nonperiodic. The question addressed in this paper is whether nonperiodicity persists at low but positive temperature. We present arguments, mostly numerical, that this is indeed the case. In particular, we define an appropriate order parameter, prove that it is identically zero at high temperatures, and show by Monte Carlo simulation that it is nonzero at low temperatures

Phase transition in a static granular system

We find that a column of glass beads exhibits a well-defined transition between two phases that differ in their resistance to shear. Pulses of fluidization are used to prepare static states with well-defined particle volume fractions $\phi$ in the range 0.57-0.63. The resistance to shear is determined by slowly inserting a rod into the column of beads. The transition occurs at $\phi=0.60$ for a range of speeds of the rod.Comment: 4 pages, 4 figures. The paper is significantly extended, including new dat