22 research outputs found

    D-brane width

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    Loop quantum gravity predicts that there are non-zero minimal area, and non-zero minimal volume in (3+1) dimensions. Given this, one can easily guess that one will have a non-zero minimal 9-volume in (9+1) dimensions. Therefore, in this paper, we argue that not only D9-brane but also Dp-brane for p less than 9 has a 9-volume. This idea is new, as the present view states that such a Dp-brane has p-volume but no 9 volume. To demonstrate this, first, we equate D8-brane action with D9-brane action and show that 9th direction which is perpendicular to D8-brane has non-zero width. We repeat this step for different ps; we equate Dp-brane action with Dp-1 brane action. By this iteration and induction we conclude that Dp-brane has non-zero widths for each of (9-p) directions perpendicular to the Dp-brane, and therefore, non-zero volume. When antisymmetric tensor and field strength are zero, this width is calculated to be 2 pi sqrt(alpha') for all (9-p) directions. For non-vanishing antisymmetric tensor and field strength, the width receives small corrections. In this paper, we only calculate up to the first order correction.Comment: 4 pages, no figures, argument based on loop quantum gravity adde

    Black Hole Entropy Prediction without Immirzi Parameter

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    In our earlier paper "Corrections to the Bekenstein-Hawking entropy and the Hawking radiation spectrum", arXiv:0910.2755, we provided two concrete numerical evidences for the new area spectrum based on the Einstein-Kaufman pseudo tensor as opposed to the Ashtekar variables: namely, the reproduction of the Bekenstein-Hawking entropy without fixing Immirzi parameter and the reproduction of the Hawking radiation spectrum. In this article, we provide another concrete, numerical evidence for this new area spectrum; there was a constant in our earlier article, which was inversely proportional to the density of state, and which we could not fix a priori. Nevertheless, in our earlier article, we obtained this constant to be around 172~173 by fitting it to the Planck radiation spectrum. In this article, we calculate this value using another method. We obtain 172.87...which implies consistency.Comment: 5 page

    Inflation and the late time acceleration from Hossenfelder-Verlinde gravity

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    We show that Hossenfelder's covariant formulation of Verlinde's emergent gravity predicts inflation and the late-time acceleration at the same time, without assuming a separate field such as inflaton, whose sole purpose is producing inflation. In particular, for the current deceleration parameter q=βˆ’0.95q=-0.95 to βˆ’0.55-0.55, we obtained Ξ»2\lambda^2, the mass of the imposter field, from 1.85Γ—1041.85\times 10^4 to 2.26Γ—1042.26\times 10^4. We also note that the value of Ξ»\lambda around q=βˆ’0.93q=-0.93 coincides with the inverse of fine structure constant.Comment: Previous numerical mistakes fixed. Simulations for four different values of q. Connection with the fine structure constant suggeste