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Does lambda evolve?

  1. Mar 18, 2008 #1

    jal

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    Does lambda evolve?
    Some people have been working on this question.

    http://arxiv.org/abs/0801.1334
    Collider Physics and Cosmology
    Authors: Jonathan L. Feng
    (Submitted on 8 Jan 2008)
    ====
    http://arxiv.org/abs/0707.3778v1
    Renormalization group running cosmologies - from a scale setting to holographic dark energy
    Authors: Branko Guberina
    (Submitted on 25 Jul 2007)
    =======

    http://arxiv.org/abs/gr-qc/0702087
    Renormalization-group running cosmologies and the generalized second law
    Authors: R. Horvat
    (Submitted on 15 Feb 2007 (v1), last revised 22 Mar 2007 (this version, v3))
    http://arxiv.org/abs/astro-ph/0404204
    Holography and Variable Cosmological Constant
    Authors: R. Horvat
    (Submitted on 9 Apr 2004 (v1), last revised 8 Sep 2004 (this version, v4))
    ======
    http://arxiv.org/abs/astro-ph/0407295
    Accelerating Universe with a dynamic cosmological term
    Authors: Saibal Ray, Utpal Mukhopadhyay, Xin-He Meng
    (Submitted on 14 Jul 2004 (v1), last revised 4 Jun 2007 (this version, v2))
    =====
    http://arxiv.org/abs/astro-ph/0606448
    Concerning the instantaneous mass and the extent of an expanding universe
    Authors: H.J. Fahr, Michael Heyl
    (Submitted on 19 Jun 2006 (v1), last revised 4 Dec 2006 (this version, v2))

    ----------------
    http://arxiv.org/abs/astro-ph/0606048
    About universes with scale-related total masses and their abolition of presently outstanding cosmological problems
    Authors: H.J. Fahr, M. Heyl
    (Submitted on 2 Jun 2006 (v1), last revised 4 Dec 2006 (this version, v2))
    ------------
    Cosmic vacuum energy decay and creation of cosmic matter.
    Hans-Jörg Fahr, Michael Heyl
    Argelander Institute for Astronomy, University of Bonn, 53121, Bonn, Germany, hfahr@astro.uni-bonn.de.
    Source: Naturwissenschaften, Volume 94, Number 9, September 2007 , pp. 709-724(16)
    Publisher: Springer
    Abstract:
    In the more recent literature on cosmological evolutions of the universe, the cosmic vacuum energy has become a nonrenouncable ingredient. The cosmological constant Λ, first invented by Einstein, but later also rejected by him, presently experiences an astonishing revival. Interestingly enough, it acts like a constant vacuum energy density would also do. Namely, it has an accelerating action on cosmic dynamics, without which, as it appears, presently obtained cosmological data cannot be conciliated with theory. As we are going to show in this review, however, the concept of a constant vacuum energy density is unsatisfactory for very basic reasons because it would claim for a physical reality that acts upon spacetime and matter dynamics without itself being acted upon by spacetime or matter.
    =======
    http://arxiv.org/abs/0803.2546
    Primordial Entropy Production and Lambda-driven Inflation from Quantum Einstein Gravity
    Authors: Alfio Bonanno, Martin Reuter
    (Submitted on 17 Mar 2008)
    “…the running cosmological constant _(k) changes by about 120 orders of magnitude between k-values of the order of the Planck mass and macroscopic scales,…

    …. We are thus led to suspect that, because of the decreasing cosmological constant, there is a
    continuous inflow of energy into the cosmological fluid contained in an expanding Universe…

    …. The assumption that the matter system must allow for an unhindered energy exchange with _
    is essential, see refs. [25, 27]….”
    -----------------
    http://arxiv.org/abs/0708.1317
    Functional Renormalization Group Equations, Asymptotic Safety, and Quantum Einstein Gravity
    Authors: Martin Reuter, Frank Saueressig
    (Submitted on 9 Aug 2007)
    http://arxiv.org/abs/0709.3851
    Asymptotic Safety
    Authors: R. Percacci
    (Submitted on 24 Sep 2007)


    http://xxx.lanl.gov/abs/hep-th/0603022
    Quantum gravity and the standard model
    Authors: Sundance O. Bilson-Thompson, Fotini Markopoulou, Lee Smolin
    (Submitted on 3 Mar 2006 (v1), last revised 21 Apr 2007 (this version, v2))
    =======
    jal
     
  2. jcsd
  3. Mar 18, 2008 #2

    Kea

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    There is no [itex]\Lambda[/itex], classically speaking. No Dark Force. Zippo. Nada. Done away with.
     
  4. Mar 19, 2008 #3

    Demystifier

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    What is that suppose to mean? :confused:

    By the way, I have also been working on that problem, as a coauthor with some of the authors mentioned above. I believe that it is safe to say that the answer to the question "Does Lambda evolve?" is not yet clear.
     
  5. Mar 19, 2008 #4

    George Jones

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    Kea might mean possibility 3) from post #32 of this thread.
     
  6. Mar 19, 2008 #5

    jal

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    Hi Demystifier
    Would you be able to tell us which approach you are working on?
    Would you have some links of other approaches, (which I would like to read).
    jal
     
  7. Mar 19, 2008 #6

    Kea

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    And as I pointed out some years ago in a short paper, referenced in the above papers, although the association of q-deformation with [itex]\Lambda[/itex] may appear to suggest a positive, or indeed variable value, the classical limit inevitably drives [itex]\Lambda[/itex] towards zero in the emergent spacetime. See also Lunsford, Riofrio, Pitkanen, Wiltshire et al. They all have compelling explanations for a zero CC.
     
  8. Mar 19, 2008 #7

    Haelfix

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    Umm, there is no good reason why lambda should be zero theoretically, either at the classical level or at the quantum level.

    Before the Supernova and CMB measurements erased most hope for an identically zero CC, people were desperatedly trying to find a good mechanism (say a symmetry principle) to make it zero. None were found, and various theorems preventing plausible zero scenarios were written down. That is why Weinberg, in frustration, wrote down his now infamous anthropic paper.

    If people could make it go away, everyone would jump on the solution b/c it is so unlovely aesthetically.
     
  9. Mar 19, 2008 #8

    Kea

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    People should look harder. People should be jumping on this option. Of course it has to come from a quantum gravitational principle, because its not in GR or the SM. All of the abovementioned ideas use related variants of a Machian holographic principle - but not a string theoretic one.
     
    Last edited: Mar 19, 2008
  10. Mar 19, 2008 #9

    jal

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    Hi Kea
    You made me work hard. (It wasn't needed/justified)
    Are these the papers that you are referring.
    http://arxiv.org/abs/0712.3984
    Dark energy without dark energy
    Authors: David L. Wiltshire
    (Submitted on 24 Dec 2007)

    p. 28
    If one replaces the words “dark energy” by “voids” in the standard qualitative
    explanation, then a probable description of the ISW effect in the FB model
    emerges.

    A true “concordance cosmology” should agree with all reliable observations,
    and not just a carefully selected subset. A glance at Table 2 reveals that
    there are many anomalies in the standard _CDM model.

    http://arxiv.org/abs/gr-qc/0503099
    Viable inhomogeneous model universe without dark energy from primordial inflation
    David L. Wiltshire
    (Submitted on 23 Mar 2005 (v1), last revised 11 Jul 2005 (this version, v5))
    Citation of this earlier work (21)
    http://www.citebase.org/search?type...ted+By&identifier=oai:arXiv.org:gr-qc/0503099
     
    Last edited: Mar 19, 2008
  11. Mar 19, 2008 #10

    Kea

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    That's a start, although this analysis is purely classical.
     
  12. Mar 19, 2008 #11

    jal

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    Coincidence on a cosmic scale does not "just" happen.
    Has anyone looked at and analyzed the fact that the "bubbles' are "coincidently" the same as sphere packing? What is the mechanism causing this?
    jal
     
    Last edited: Mar 19, 2008
  13. Mar 19, 2008 #12

    Kea

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    The question is: what exactly do you mean by the phrase the same as sphere packing? Now I happen to be interested in the mathematics of sphere packing, partly for cosmological reasons as you say, but there are a LOT of details in between that and this.
     
  14. Mar 19, 2008 #13
    I believe jal, if I understand you correctly, that what you're trying to get at with the sphere and sphere packing model might be something like this, let's say you have an atom or a bauble or a pearl and when you super position the nucleic substance only half of the most outer layer shells enters a corporeal phaseout state of infinite possibility's all relying on the one flat constant concrete charge to fix void from, underlined in possibility of chance and catastrophe. Eventually the possibilities would begin to collapse and cause a dark fix infiltrative time tear to begin to open on the positive space side and export the particles to and through to the other side in order to undergo the process of certain possibility discontinuation. The infinite and unknown possibilities remaining in the bauble achieve a state of regressed time inversion independent of either side. The photons are spliced, inverted and travel, rise and engage in an internal concentrated bubble of a corporeal phaseout. Zero point gravity is inside the holo shell, the outer magnetically exploded and expanded edges are the 'Inra In Bows' of potentials, possibility and chance. A bubble rising out in cylinder from within a triple helix spiral, or a trinity of the genome finally ascending...:uhh:

    But of course you certainly know much more than I do and I'm just learning :redface:
    Tell me what you think, if anything?

    Does lambda evolve? My point says yes...

    -Pictosurial Dreamlog
     
    Last edited: Mar 19, 2008
  15. Mar 19, 2008 #14

    jal

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    Pictosurial
    Sorry but your eloguent description did not evoke anything in me. (No associations) :confused:
    Welcome!

    Kea
    I raised the point for the very reason that it would take knowledge that I do not possess to be able to try to identify a possible mechanism.
     
  16. Mar 19, 2008 #15
    Ok so let me setup a geometric mathematical provocation.

    Combine, catalog, symbolize and mutate or fuse the following...
    +1³ gnomonic stance
    -1³ gnomonic dance
    A square within a circle
    An open six space cube
    A hypercube balanced within the chrono cross
    A hexagon holo by cube
    A time riddled specter in phaseout fugue
    The triple helix spiral all rising out of and into man's room

    Holographic double imaging principles and strings are all in full effect here as is synesthesia and man's pictorial amnesia...

    Now try harder and give me some thoughts...:shy:
     
  17. Mar 20, 2008 #16

    Kea

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    Any mathematician could easily do that. Such loose terms are not relevant to this discussion.
     
  18. Mar 20, 2008 #17
    Hi Kea,

    Interesting that you mention this. I've started working on a "Machian holographic-like" principle in the context of Braneworlds some years ago. The braneworld scenario served just as an exercise. The idea does not necessarily need, in a fundamental way, the braneworld.

    http://xxx.lanl.gov/abs/gr-qc/0411038
    A Note on the Integral Formulation of Einstein's Equations Induced on a Braneworld
    Gen.Rel.Grav. 37 (2005) 959-965

    I did not get back to these ideas, but I intend to, as soon as I find more time.

    Best,
    Christine
     
  19. Mar 20, 2008 #18

    jal

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    Hi ccdantas
    You have a lot of good references.
    http://xxx.lanl.gov/abs/gr-qc/0411038
    A Note on the Integral Formulation of Einstein's Equations Induced on a Braneworld
    Authors: Christine C. Dantas
    (Submitted on 8 Nov 2004)
    We argue that the role of the surface term (the sourcefree contribution) in the braneworld scenario may be quite subtler than in the 4D formulation. This may pose, for instance, an interesting issue to the cosmological constant problem.
    ----------
    Question
    I could not help but noticed that if instead of using the Randall-Sundrum type 2 model [14], description, could you replace it with Schwarzschild radius, event horizon, cosmic horizon to achieve the same thing. H.J. Fahr and Michael Heyl seem to have done something similar.
    --------
    One of your references, R. G. Vishwakarma, has continued publishing interesting papers.
    http://lanl.arxiv.org/find/gr-qc/1/au:+Vishwakarma_R/0/1/0/all/0/1
    since publishing
    http://lanl.arxiv.org/abs/gr-qc/0205075
    A Machian Model of Dark Energy
    Authors: R. G. Vishwakarma
    (Submitted on 17 May 2002 (v1), last revised 19 Aug 2002 (this version, v2))

    This forces one to think whether the Mach's ideas and the cosmological constant are interrelated in some way.
    --------
    http://lanl.arxiv.org/abs/astro-ph/0211285v3
    Can brane cosmology with a vanishing \Lambda explain the observations?
    Authors: R. G. Vishwakarma (IUCAA), Parampreet Singh (IUCAA)
    (Submitted on 13 Nov 2002 (v1), last revised 21 Mar 2003 (this version, v3))
    It should be noted however that despite its consistency with the observations, the nature of dark energy is a mystery at present. It does not seem to resemble any known form of matter tested in the laboratory. As yet, we have no direct indication that it really exists. In fact, a more natural value of the cosmological constant is zero (which could either be due to some symmetry or due to a dynamical adjustment
    mechanism) rather than an extremely small value but still non-zero.
    In this paper, we show that the present observations …. can successfully be explained without a lambda term and the universe is still decelerating.

    His latest
    http://lanl.arxiv.org/abs/0801.2973
    A Model to Explain Varying $\Lambda$, $G$ and $\sigma^2$ Simultaneously
    Authors: R. G. Vishwakarma
    (Submitted on 18 Jan 2008)
    ------
    When I check the citations, I find other authors who have been dealing with the subjects of this thread.
    jal
     
  20. Mar 20, 2008 #19
    Hi jal,

    What I meant was that you can use the integral formulation of Einsteins equations in other contexts. The main problem is to give a precise meaning to Mach's Principle. The integral formulation provides that to a certain extent.

    Christine
     
  21. Mar 20, 2008 #20

    Kea

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    Hi Christine. Yes, I recall your paper. Constraining allowed spacetimes in this way is one concrete implementation of a Machian principle. I expect that the GR limit of QG will come with such constraints attached. Thus GR is viewed as 'incomplete' as a theory.
     
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