Effects of the Generalized Uncertainty Principle on Compact Stars

Based on the generalized uncertainty principle (GUP), proposed by some approaches to quantum gravity such as string theory and doubly special relativity theories, we investigate the effect of GUP on the thermodynamic properties of compact stars with two different components. We note that the existence of quantum gravity correction tends to resist the collapse of stars if the GUP parameter $\alpha$ is taking values between Planck scale and electroweak scale. Comparing with approaches, it is found that the radii of compact stars are found smaller. Increasing energy almost exponentially decreases the radii of compact stars.Comment: 7 pages, two figures, to appear in IJMP

Planck-Scale Corrections to Friedmann Equation

Recently, Verlinde proposed that gravity is an emergent phenomenon which originates from an entropic force. In this work, we extend Verlinde's proposal to accommodate generalized uncertainty principles (GUP), which are suggested by some approaches to \emph{quantum gravity} such as string theory, black hole physics and doubly special relativity (DSR). Using Verlinde's proposal and two known models of GUPs, we obtain modifications to Newton's law of gravitation as well as the Friedmann equation. Our modification to the Friedmann equation includes higher powers of the Hubble parameter which is used to obtain a corresponding Raychaudhuri equation. Solving this equation, we obtain a leading Planck-scale correction to Friedmann-Robertson-Walker (FRW) solutions for the $p=\omega \rho$ equation of state.Comment: 15 pages, no figure, to appear in Central Eur.J.Phys. arXiv admin note: text overlap with arXiv:1301.350

Modified Newton's Law of Gravitation Due to Minimal Length in Quantum Gravity

A recent theory about the origin of the gravity suggests that the gravity is originally an entropic force. In this work, we discuss the effects of generalized uncertainty principle (GUP) which is proposed by some approaches to quantum gravity such as string theory, black hole physics and doubly special relativity theories (DSR), on the area law of the entropy. This leads to a $\sqrt{Area}$-type correction to the area law of entropy which imply that the number of bits $N$ is modified. Therefore, we obtain a modified Newton's law of gravitation. Surprisingly, this modification agrees with different sign with the prediction of Randall-Sundrum II model which contains one uncompactified extra dimension. Furthermore, such modification may have observable consequences at length scales much larger than the Planck scale.Comment: 12 pages, no figures, references adde

No Existence of Black Holes at LHC Due to Minimal Length in Quantum Gravity

We investigate the impact of the Generalized Uncertainty Principle (GUP), proposed by some approaches to quantum gravity such as String Theory and Doubly Special Relativity Theories (DSR) on the production of mini black holes, and show that the minimum black hole mass is formed at energies higher than the energy scales of LHC which possibly agrees with the recent experimental results of LHC [arXiv:1012.3375, arXiv:1206.5663] .Comment: 13 pages, no figures, references adde

Discreteness of time in the evolution of the universe

In this paper, we will first derive the Wheeler-DeWitt equation for the generalized geometry which occurs in M-theory. Then we will observe that M2-branes act as probes for this generalized geometry, and as M2-branes have an extended structure, their extended structure will limits the resolution to which this generalized geometry can be defined. We will demonstrate that this will deform the Wheeler-DeWitt equation for the generalized geometry. We analyze such a deformed Wheeler-DeWitt equation in the minisuperspace approximation and observe that this deformation can be used as a solution to the problem of time. This is because this deformation gives rise to time crystals in our universe due to the spontaneous breaking of time re-parametrization invariance.Comment: 20 pages, 0 figures, To appear in IJMP

Generalized Uncertainty Principle as a Consequence of the Effective Field Theory

We will demonstrate that the generalized uncertainty principle exists because of the derivative expansion in the effective field theories. This is because, in the framework of the effective field theories, the minimum measurable length scale has to be integrated away to obtain the low energy effective action. We will analyze the deformation of a massive free scalar field theory by the generalized uncertainty principle, and demonstrate that the minimum measurable length scale corresponds to a second more massive scale in the theory, which has been integrated away. We will also analyze CFT operators dual to this deformed scalar field theory, and observe that scaling of the new CFT operators indicates that they are dual to this more massive scale in the theory. We will use holographic renormalization to explicitly calculate the renormalized boundary action with counterterms for this scalar field theory deformed by the generalized uncertainty principle and show that the generalized uncertainty principle contributes to the matter conformal anomaly.Comment: 15 pages, no figures, Accepted for Publication in Physics Letters