Absence of Higher Order Corrections to Noncommutative Chern-Simons Coupling

We analyze the structure of noncommutative pure Chern-Simons theory systematically in the axial gauge. We show that there is no IR/UV mixing in this theory in this gauge. In fact, we show, using the usual BRST identities as well as the identities following from vector supersymmetry, that this is a free theory. As a result, the tree level Chern-Simons coefficient is not renormalized. It also holds that the Chern-Simons coefficient is not modified at finite temperature. As a byproduct of our analysis, we prove that the ghosts completely decouple in the axial gauge in a noncommutative gauge theory.Comment: LaTeX file, 16 pages, no figur

Generalized uncertainty principle and correction value to the black hole entropy

Recently, there has been much attention devoted to resolving the quantum corrections to the Bekenstein-Hawking entropy of the black hole. In particular, many researchers have expressed a vested interest in the coefficient of the logarithmic term of the black hole entropy correction term. In this paper, we calculate the correction value of the black hole entropy by utilizing the generalized uncertainty principle and obtain the correction term caused by the generalized uncertainty principle. Because in our calculation we think that the Bekenstein-Hawking area theorem is still valid after considering the generalized uncertainty principle, we derive that the coefficient of the logarithmic term of the black hole entropy correction term is negative. This result is different from the known result at present. Our method is valid not only for single horizon spacetime but also for double horizons spacetime. In the whole process, the physics idea is clear and calculation is simple. It offers a new way for studying the condition that Bekenstein-Hawking area theorem is valid

Shelf life and quality of Sorboti lemon as affected by different chemicals and storage temperature

A laboratory experiment was conducted with different chemicals and storage temperature (Kinetin + 4°C, kinetin + 15°C, kinetin + 25°C, potash alum + 4°C, potash alum + 15°C, potash alum + 25°C, hot water + 4°C, hot water + 15°C, hot water + 25°C, without treatment + 4°C, without treatment + 15°C and without treatment + 25°C) at the department of Horticulture of Bangabandhu Sheikh Mujibur Rahaman Agricultural University during June to December 2017. The aim was the study to find out the suitable method to increase shelf life of Sorboti lemon. During storage fruit decay, weight loss and total soluble solid (TSS) increased. While juice content, ascorbic acid content decreased with the increase in storage temperature. Minimum fruit decay (50%) was recorded up to 70 Days after storage (DAS) at 4°C in hot water treatment and fruit decayed (90%) at 4°C was recorded up to 70 DAS in Kinetin treatment. Minimum loss of fruit weight was recorded at 4°C (7.10% and 11.95%) at 70 DAS when stored in hot water and kinetin, respectively. Maximum juice content (50.11%) after 70 DAS at 4°C in hot water treatment which was followed by Kinetin treatment storage at 4°C (40.10%). The TSS was found almost static at 70 days after storage but ascorbic acid content decreased (59.59 mg/100ml to 43.36 mg/100ml and 63.10 mg/100 ml to 49.11 mg/100ml) from its initial content in hot water and kinetin at 4°C temperature. At 15°C temperature, it can only possible up to 35 days. So, considering fruit decay, weight loss, TSS and juice content lemon could be stored up to 70 DAS at 4°C both under hot water and kinetin treatment. Storing can be done in 35 DAS at 15°C both hot water and kinetin treatment

Gravitational non-commutativity and G\"odel-like spacetimes

We derive general conditions under which geodesics of stationary spacetimes resemble trajectories of charged particles in an electromagnetic field. For large curvatures (analogous to strong magnetic fields), the quantum mechanicical states of these particles are confined to gravitational analogs of {\it lowest Landau levels}. Furthermore, there is an effective non-commutativity between their spatial coordinates. We point out that the Som-Raychaudhuri and G\"odel spacetime and its generalisations are precisely of the above type and compute the effective non-commutativities that they induce. We show that the non-commutativity for G\"odel spacetime is identical to that on the fuzzy sphere. Finally, we show how the star product naturally emerges in Som-Raychaudhuri spacetimes.Comment: Two sections added (Relation to the fuzzy sphere, Emergence of the star product). 10 pages, Revtex. To appear in General Relativity and Gravitatio

Structural and magnetization behaviors of Ni substituted Li-Mg ferrites

Magnetization behaviors of Ni-substituted LixMg0.5Ni0.5-2xFe2+xO4 ferrites, where x = 0.25, 0.20, 0.15, 0.10 and 0.00 synthesized by standard ceramic technology sintered at 1300°C in air for 5 hours has been presented in the present study. The bulk density and lattice constants of the samples found to be decreased with the increase in the Ni-content for the x values from 0.25 to 0.00. DC electrical resistivity has found to show highest magnitude at room temperature and decreases with further increase in temperature. Magnetization of the samples has been measured as a function of the field using hysteresis loop tracer at 30°C. It was observed that addition of nickel in polycrystalline Li-Mg ferrites plays an important role in modification of structural and magnetization characteristics

Kontsevich product and gauge invariance

We analyze the question of $U_{\star} (1)$ gauge invariance in a flat non-commutative space where the parameter of non-commutativity, $\theta^{\mu\nu} (x)$, is a local function satisfying Jacobi identity (and thereby leading to an associative Kontsevich product). We show that in this case, both gauge transformations as well as the definitions of covariant derivatives have to modify so as to have a gauge invariant action. We work out the gauge invariant actions for the matter fields in the fundamental and the adjoint representations up to order $\theta^{2}$ while we discuss the gauge invariant Maxwell theory up to order $\theta$. We show that despite the modifications in the gauge transformations, the covariant derivative and the field strength, Seiberg-Witten map continues to hold for this theory. In this theory, translations do not form a subgroup of the gauge transformations (unlike in the case when $\theta^{\mu\nu}$ is a constant) which is reflected in the stress tensor not being conserved.Comment: 7 page