The Schrodinger equation with Hulthen potential plus ring-shaped potential

We present the solutions of the Schr$\ddot{o}$dinger equation with the Hulth$\acute{e}$n potential plus ring-shape potential for $\ell\neq 0$ states within the framework of an exponential approximation of the centrifugal potential.Solutions to the corresponding angular and radial equations are obtained in terms of special functions using the conventional Nikiforov-Uvarov method. The normalization constant for the Hulth$\acute{e}$n potential is also computed.Comment: Typed with LateX,12 Pages, Typos correcte

Growth and yield of Vigna radiata L.) under Terminalia arjuna and Mitragyna parvifolia based agrisilvicultural system

The present investigation was carried out in an agrisilvicultural system with treatments involving silvicultural component of 20 years old Terminalia arjuna Bedd. (Arjun) and Mitragyna parvifolia Korth (Kalam) intercropped with agricultural component of four varieties of green gram (Vigna radiata L.) viz. Pusa Vishal, GM-3, GM-4 and K-851. All the varieties of green gram were compared for growth and yield parameters like plant height (cm), number of leaves, number of branches per plant, total grain yield per plant as well as per plot at harvestablestage under Arjuna and Kalam trees. All the varieties of green gram performed superior in terms of number of leaves, numbers of branches, grain yield (per plant and per plot basis) under open condition as compared to crops under Arjuna and Kalam. However, only the plant height was found to be highest under Arjun, followed by Kalam trees. Among all the varieties tested, K-851 variety showed superiority for number of leaves (12.31) and number of branches per plant (3.96) and grain yield (2.66 gm per plant and 0.80 kg per plot) as compared to other varieties (at P=0.05). Therefore, this variety is suggested to grow in south Gujarat condition. Further, comparatively lower yield of crop under tree cover could be due to shade effect, which can be managed by regular pruning of tree branches

Observational Constraints on Theories with a Blue Spectrum of Tensor Modes

Motivated by the string gas cosmological model, which predicts a blue tilt of the primordial gravitational wave spectrum, we examine the constraints imposed by current and planned observations on a blue tilted tensor spectrum. Starting from an expression for the primordial gravitational wave spectrum normalized using cosmic microwave background observations, pulsar timing, direct detection and nucleosynthesis bounds are examined. If we assume a tensor to scalar ratio on scales of the CMB which equals the current observational upper bound, we obtain from these current observations constraints on the tensor spectral index of $n_{T} \lesssim 0.79$, $n_{T} \lesssim 0.53$, and $n_{T} \lesssim 0.15$ respectively.Comment: 12 pages, 1 figure, 2 references added, relationship of this work with Ref. 20 adde

Effects of gamma rays on germination and growth in Jatropha curcas L.

The present investigation was carried out at the Forestry Research Farm, Navsari Agricultural University; Navsari to evaluate the gamma rays at 10 kR, 20 kR and 30 kR induced variability in Jatropha curcas L. on germination, growth and yield for seven Jatropha genotypes (Phule J-1, Urlikanchan, Hansraj, SKN Big, Chhatrapati, Hansot and MPJ-55). The significantly maximum germination percentage (66.96%), seedling survival (74.18%), seedling collar diameter (0.958cm), shoot length (49.442cm), number of leaves per seedling (7.757) and leaf area (37. 58)was observed in Chhatrapati genotype during nursery stage. While low rate of gamma rays treatment (10 kR) had stimulatory effect for germination percentage, seedling survival, seedling collar diameter, shoot length, number of leaves per seedling and leaf area. However, higher gamma rays doses (30 kR) drastically reduced all studied characters. The interaction effect of genotype and gamma rays were significant for number of leaves per seedling. Further, it was not significant in other traits like germination percentage, seedling survival, seedling collar diameter, shoot length and leaf area

Inflation with a stringy minimal length, reworked

In this paper we revisit the formulation of scalar field theories on de Sitter backgrounds subject to the generalized uncertainty principle (GUP). The GUP arises in several contexts in string theory, but is most readily thought of as resulting from using strings as effective probes of geometry, which suggests an uncertainty relation incorporating the string scale $l_s$. After reviewing the string theoretic case for the GUP, which implies a minimum length scale $l_s$, we follow in the footsteps of Kempf and concern ourselves with how one might write down field theories which respect the GUP. We uncover a new representation of the GUP, which unlike previous studies, readily permits exact analytical solutions for the mode functions of a scalar field on de Sitter backgrounds. We find that scalar fields cannot be quantized on inflationary backgrounds with a Hubble radius $H^{-1}$ smaller than the string scale, implying a sensibly stringy (as opposed to Planckian) cutoff on the scale of inflation resulting from the GUP. We also compute $(H l_s)^2$ corrections to the two point correlation function analytically and comment on the future prospects of observing such corrections in the fortunate circumstance our universe is described by a very weakly coupled string theory.Comment: To appear in JHEP. Sub-section discussing how our approach avoids certain ordering ambiguities adde

Recurrences in Driven Quantum Systems

We consider an initially bound quantum particle subject to an external time-dependent field. When the external field is large, the particle shows a tendency to repeatedly return to its initial state, irrespective of whether the frequency of the field is sufficient for escape from the well. These recurrences, which are absent in a classical calculation, arise from the system evolving primarily like a free particle in the external field.Comment: 10 pages in RevTeX format, with three PS files appende

Systematic study of X-ray Cavities in the brightest galaxy of the Draco Constellation NGC 6338

We present results based on the systematic analysis of currently available Chandra archive data on the brightest galaxy in the Draco constellation NGC 6338, in order to investigate the properties of the X-ray cavities. In the central ~6 kpc, at least a two and possibly three, X-ray cavities are evident. All these cavities are roughly of ellipsoidal shapes and show a decrement in the surface brightness of several tens of percent. In addition to these cavities, a set of X-ray bright filaments are also noticed which are spatially coincident with the H{\alpha} filaments over an extent of 15 kpc. The H{\alpha} emission line filaments are perpendicular to the X- ray cavities. Spectroscopic analysis of the hot gas in the filaments and cavities reveal that the X-ray filaments are cooler than the gas contained in the cavities. The emission line ratios and the extended, asymmetric nature of the H{\alpha} emission line filaments seen in this system require a harder ionizing source than that produced by star formation and/or young, massive stars. Radio emission maps derived from the analysis of 1.4 GHz VLA FIRST survey data failed to show any association of these X-ray cavities with radio jets, however, the cavities are filled by radio emission. The total power of the cavities is 17\times 1042 erg s-1 and the ratio of the radio luminosity to cavity power is ~ 10-4, implying that most of the jet power is mechanical.Comment: The paper contains 12 figures and 3 tables, Accepted 2011 December 7 for publication in MNRA

Inaccessible Singularities in Toral Cosmology

The familiar Bang/Crunch singularities of classical cosmology have recently been augmented by new varieties: rips, sudden singularities, and so on. These tend to be associated with final states. Here we consider an alternative possibility for the initial state: a singularity which has the novel property of being inaccessible to physically well-defined probes. These singularities arise naturally in cosmologies with toral spatial sections.Comment: 10 pages, version to appear in Classical and Quantum Gravit