On the origin of generalized uncertainty principle from compactified M5-brane

In this paper, we demonstrate that compactification in M-theory can lead to a deformation of field theory consistent with the generalized uncertainty principle (GUP).We observe that the matter fields in the M3-brane action contain higher derivative terms. We demonstrate that such terms can also be constructed from a reformulation of the field theory by the GUP. In fact, we will construct the Heisenberg algebra consistent with this deformation, and explicitly demonstrate it to be the Heisenberg algebra obtained from the GUP. Thus, we use compactification in M-theory to motivate for the existence of the GUP.Comment: 5 pages, accepted by Mod. Phys. Lett.

String-Dust Distributions with the Kerr-NUT symmetry

We attempt to solve the Einstein equations for string dust and null flowing radiation for the general axially symmetric metric, which we believe is being done for the first time. We obtain the string-dust and radiating generalizations of the Kerr and the NUT solutions. There also occurs an interesting case of radiating string-dust which arises from string-dust generalization of Vaidya's solution of a radiating star.Comment: 15 pages, TeX version. tex error correcte

Teleparallel loop quantum cosmology in a system of intersecting branes

Recently, some authors have removed the big bang singularity in teleparallel Loop Quantum Cosmology (LQC) and have shown that the universe may undergo a number of oscillations. We investigate the origin of this type of teleparallel theory in a system of intersecting branes in M-theory in which the angle between them changes with time. This system is constructed by two intersecting anti-D8-branes, one compacted D4-brane and the other a D3-brane. These branes are built by joining M0-branes which develop in decaying fundamental strings. The compacted D4-brane is located between two intersecting anti-D8 branes and glues to one of them. Our universe is located on the D3 brane which wraps the D4 brane from one end and sticks to one of the anti-D8 branes from another one. In this system, there are three types of fields, corresponding to compacted D4 branes, intersecting branes and D3-branes. These fields interact with each other and make the angle between branes oscillate. By decreasing this angle and approaching the intersecting anti-D8 branes towards each other, the D4 brane rolls, the D3 brane wraps around the D4 brane, and t he universe contracts. By separating the intersecting branes and increasing the angle, the D4 brane rolls in the opposite direction, the D3 brane separates from it and the expansion branch begins. Also, the interaction between branes in this system gives us the exact form of the relevant Lagrangian for teleparallel LQC.Comment: 11 page

Global monopole in scalar tensor theory

The well known monopole solution of Barriola and Vilenkin (BV) resulting from the breaking of a global SO(3) symmetry is extended in general relativity along with a zero mass scalar field and also in Brans-Dicke(BD) theory of gravity.In the case of BD theory, the behaviour of spacetime and other variables such as BD scalar field and the monopole energy density have been studied numerically.For monopole along with a zero mass scalar field, exact solutions are obtained and depending upon the choice of arbitary parameters, the solutions either reduce to the BV case or to a pure scalar field solution as special cases.It is interesting to note that unlike the BV case the global monopole in the BD theory does exert gravitational pull on a test particle moving in its spacetime.Comment: 12 pages LaTex, 3 postscript figures, Communicated to Class.Quant.Gra