Brans-Dicke theory: Jordan vs Einstein Frame

It is well known that, in contrast to general relativity, there are two conformally related frames, the Jordan frame and the Einstein frame, in which the Brans-Dicke theory, a prototype of generic scalar-tensor theory, can be formulated. There is a long standing debate on the physical equivalence of the formulations in these two different frames. It is shown here that gravitational deflection of light to second order accuracy may observationally distinguish the two versions of the Brans-Dicke theory.Comment: 10 pages, Accepted by Mod. Phys. Letts.

Recent Advances in the Technology of Aluminium- Magnesium Alloys

ALLOYS of aluminium with copper. to which smallamounts of manganese. magnesium and silicon are added, belong to the well known group of alloys termed "'Duralumin ', and were amongst the earliest of aluminium alloys to be used commercially on account of their age-hardening characteristics. Alloys of aluminium with magnesium as the principal alloying element, first attracted the interest of investigators as early as 1900, and since then, cast alloys containing as much as 10% magnesium have been used for specified purpose

Strong field gravitational lensing in scalar tensor theories

Strong field gravitational lensing in the Brans-Dicke theory has been studied. The deflection angle for photons passing very close to the photon sphere is estimated for the static spherically symmetric space-time of the theory and the position and magnification of the relativistic images are obtained. Modeling the super massive central object of the galaxy by the Brans-Dicke space-time, numerical values of different strong lensing observable are estimated. It is found that against the expectation there is no significant scalar field effect in the strong field observable lensing parameters. This observation raises question on the potentiality of the strong field lensing to discriminate different gravitational theories.Comment: 20 pages, accepted in Class. Quantum Grav., final versio

Testing gravity at the Second post-Newtonian level through gravitational deflection of massive particles

Expression for second post-Newtonian level gravitational deflection angle of massive particles is obtained in a model independent framework. Several of its important implications including the possibility of testing gravitational theories at that level are discussed.Comment: 5 pages, couple of equations of the previous version are correcte

Wormhole with varying cosmological constant

It has been suggested that the cosmological constant is a variable dynamical quantity. A class of solution has been presented for the spherically symmetric space time describing wormholes by assuming the erstwhile cosmological constant $\Lambda$ to be a space variable scalar, viz., $\Lambda$ = $\Lambda (r)$ . It is shown that the Averaged Null Energy Condition (ANEC) violating exotic matter can be made arbitrarily small.Comment: 8 pages, 2 figures, Accepted in Gen. Rel. Gra

Design and Test of a Forward Neutron Calorimeter for the ZEUS Experiment

A lead scintillator sandwich sampling calorimeter has been installed in the HERA tunnel 105.6 m from the central ZEUS detector in the proton beam direction. It is designed to measure the energy and scattering angle of neutrons produced in charge exchange ep collisions. Before installation the calorimeter was tested and calibrated in the H6 beam at CERN where 120 GeV electrons, muons, pions and protons were made incident on the calorimeter. In addition, the spectrum of fast neutrons from charge exchange proton-lucite collisions was measured. The design and construction of the calorimeter is described, and the results of the CERN test reported. Special attention is paid to the measurement of shower position, shower width, and the separation of electromagnetic showers from hadronic showers. The overall energy scale as determined from the energy spectrum of charge exchange neutrons is compared to that obtained from direct beam hadrons.Comment: 45 pages, 22 Encapsulated Postscript figures, submitted to Nuclear Instruments and Method

Donkey milk: chemical make-up, biochemical features, nutritional worth, and possible human health benefits - Current state of scientific knowledge

Milk and milk derivatives are widely consumed because of their high nutritional density. Donkey milk and milk products have been consumed since ancient times. The use of donkey milk in the human diet is gaining popularity. The abundance of antibacterial components and protective elements in donkey milk sets it apart from the milk of other animals. Like human milk, donkey milk has low fat, high lactose, and low casein/whey protein ratio. Donkey milk whey protein's anti-proliferative properties imply lung cancer treatment. Alpha-lactalbumin, a type of protein, has been found to have antiviral, anticancer, and anti-stress properties. Donkey milk, like human milk, includes a low amount of casein and a smaller quantity of beta-lactoglobulin than cow milk. Donkey milk is an alternative for newborns with cow milk protein allergy and lactose intolerance since it has a higher amount of lactose, improves palatability, and prevents allergies. Osteogenesis, arteriosclerosis therapy, cardiac rehabilitation, accelerated aging, and hypocholesterolemic diets are some areas where donkey milk is beneficial. Since it contains probiotic lactobacilli strains, fermented beverages can be made with donkey milk. Donkey milk moisturizes skin due to its high vitamin, mineral, and polyunsaturated fatty acid content. The chemical makeup and potential therapeutic benefits of donkey milk warrant additional research. This has led to a rise in interest in producing dairy goods derived from donkey milk. Donkey milk has been used to make cheese, ice cream, milk powder, and even some experimental useful fermented drinks. The present article summarises what we know about donkey milk's chemical makeup, biological functions, nutritional worth, and possible human health benefits

Strong Gravitational Lensing in a Charged Squashed Kaluza- Klein Black hole

In this paper we investigate the strong gravitational lensing in a charged squashed Kaluza-Klein black hole. We suppose that the supermassive black hole in the galaxy center can be considered by a charged squashed Kaluza-Klein black hole and then we study the strong gravitational lensing theory and estimate the numerical values for parameters and observables of it. We explore the effects of the scale of extra dimension $\rho_0$ and the charge of black hole $\rho_q$ on these parameters and observables.Comment: 17 pages, 10 figure

Region of Excessive Flux of PeV Cosmic Rays in the Direction Toward Pulsars PSR J1840+5640 and LAT PSR J1836+5925

An analysis of arrival directions of extensive air showers (EAS) registered with the EAS MSU and EAS-1000 prototype arrays has revealed a region of excessive flux of PeV cosmic rays in the direction toward pulsars PSR J1840+5640 and LAT PSR J1836+5925 at significance level up to 4.5sigma. The first of the pulsars was discovered almost 30 years ago and is a well-studied old radio pulsar located at the distance of 1.7pc from the Solar system. The second pulsar belongs to a new type of pulsars, discovered by the space gamma-ray observatory Fermi, pulsations of which are not observed in optical and radio wavelengths but only in the gamma-ray range of energies (gamma-ray-only pulsars). In our opinion, the existence of the region of excessive flux of cosmic rays registered with two different arrays provides a strong evidence that isolated pulsars can give a noticeable contribution to the flux of Galactic cosmic rays in the PeV energy range.Comment: 14 pages; v.2: a few remarks to match a version accepted for Astronomy Letters added. They can be found by redefining the \NEW command in the preamble of the LaTeX fil