Recent content by Danny

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    What is the proposed solution for the problem of time in General Relativity?

    Recently, I read a very intereting paper by Thomas Thiemann, It is based on this idea that if the Lagrangean for a scalar field coupled to General Relativity only contains derivatives, then it is possible to completely deparametrise the theory. This means that 1. Physical observables...
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    Interstellar radiation field between 0.1 microns and 1000 microns

    Cosmic-ray electrons and positrons propagating in the Galaxy produce diffuse gamma-rays via the inverse Compton (IC) process. The low energy target photon populations with which the cosmic-rays interact during propagation are produced by stars, this stellar light being reprocessed by...
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    Padmanabhan hologravity thread

    I think this paper is very exciting since it activates the basic idea of primary Casimir effect as a root to identify the geometrical fluctuation of space, before big bang. However, what I do not understand is that how one can talk about "charged vacuum", those vacuum bubbles which get charged...
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    What are the implications of Ansari's discovery of degeneracy in LQG?

    Marcus: Thanks for inviting me to another thread. I will read it but it seems to be too long! I will write about the quantum information appraoch soon. it is basically a thrid appraoch different from Ansari's and isolated horizon. Thanks for asking. Self-adjoint: My read is that any single node...
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    What are the implications of Ansari's discovery of degeneracy in LQG?

    I agree Chronos that Ansari's work is a critical point for LQG, if his work is right, which simply seems to be. Though, it cannot rule out or in LQG. There are some dark points Chronos. I think this is not a physical or unphysical result at all. Let me put this in this way. Lee Smolin in his...
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    What are the implications of Ansari's discovery of degeneracy in LQG?

    Recently, I read a beautiful paper in which it is proven that ANY surface in LQG contains degeneracy, no matter it being a boundary horizon or whatever else. (http://uk.arxiv.org/abs/gr-qc/0603121) This degeneracy is such that the surface degeneracy is A/4. This is a critial discovery in LQG and...
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    Robert B. Mann et al: Black String Solutions w/ Negative Cosmological Constant

    "Black string solutions with negative cosmological constant" By Robert B. Mann, Eugen Radu, Cristian Stelea It is a remarkable work in my point of view. They present an arguments for the existence of new black string solutions with negative cosmological constant. These higher-dimensional...
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    What is the moral obligation of theorists in the scientific community?

    To me MOND is a toy model not a theory.
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    Robert B. Mann et al: Black String Solutions w/ Negative Cosmological Constant

    "Black string solutions with negative cosmological constant" By Robert B. Mann, Eugen Radu, Cristian Stelea It is a remarkable work in my point of view. They present an arguments for the existence of new black string solutions with negative cosmological constant. These higher-dimensional...
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