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Categorizing different approaches to the cosmological constant problem
"... Abstract. We have found that proposals addressing the old cosmological constant problem come in various categories. The aim of this paper is to identify as many different, credible mechanisms as possible and to provide them with a code for future reference. We find that they all can be classified in ..."
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Abstract. We have found that proposals addressing the old cosmological constant problem come in various categories. The aim of this paper is to identify as many different, credible mechanisms as possible and to provide them with a code for future reference. We find that they all can be classified
A small but nonzero cosmological constant
, 1999
"... Recent astrophysical observations seem to indicate that the cosmological constant is small but nonzero and positive. The old cosmological constant problem asks why it is so small; we must now ask, in addition, why it is nonzero, and why it is positive. In this essay, we try to kill these three metap ..."
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Cited by 8 (0 self)
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Recent astrophysical observations seem to indicate that the cosmological constant is small but nonzero and positive. The old cosmological constant problem asks why it is so small; we must now ask, in addition, why it is nonzero, and why it is positive. In this essay, we try to kill these three
A small but nonzero cosmological constant ∗
, 2000
"... Recent astrophysical observations seem to indicate that the cosmological constant is small but nonzero and positive. The old cosmological constant problem asks why it is so small; we must now ask, in addition, why it is nonzero (and is in the range found by recent observations), and why it is positi ..."
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Recent astrophysical observations seem to indicate that the cosmological constant is small but nonzero and positive. The old cosmological constant problem asks why it is so small; we must now ask, in addition, why it is nonzero (and is in the range found by recent observations), and why
Revised Estimate of the Cosmological Constant
, 2001
"... The estimate of the cosmological constant is revised with account of the renormalized contribution of the ground state energy of the free fermion (neutrino) massive field. It is shown that the requirement of the renormalization group invariance leads to the value of the effective Λterm which is of ..."
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theory [1]. This is socalled old cosmological constant problem, while the new one is why it is comparable to the present mass density [2, 3]. Here we will study only the old one. This problem attracts a great interest of the physical community (just mention that the SPIRESSLAC database gives more than
Cosmology with Interacting Dark Energy
, 2003
"... The early cosmic inflation, when taken along with the recent observations that the universe is currently dominated by a low density vacuum energy, leads to at least two potential problems which modern cosmology must address. First, there is the old cosmological constant problem, with a new twist: th ..."
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The early cosmic inflation, when taken along with the recent observations that the universe is currently dominated by a low density vacuum energy, leads to at least two potential problems which modern cosmology must address. First, there is the old cosmological constant problem, with a new twist
The cosmological constant problem and quintessence
, 2002
"... Abstract. I briefly review the cosmological constant problem and the issue of dark energy (or quintessence). Within the framework of quantum field theory, the vacuum expectation value of the energy momentum tensor formally diverges as k 4 . A cutoff at the Planck or electroweak scale leads to a cos ..."
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Cited by 17 (1 self)
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Abstract. I briefly review the cosmological constant problem and the issue of dark energy (or quintessence). Within the framework of quantum field theory, the vacuum expectation value of the energy momentum tensor formally diverges as k 4 . A cutoff at the Planck or electroweak scale leads to a
The cosmological constant
"... We discuss issues related with the cosmological constant problem in the light of recent observations which tend to indicate that the expansion of the universe is presently undergoing an acceleration. Models of fundamental physics which address these issues are discussed. 1 ..."
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We discuss issues related with the cosmological constant problem in the light of recent observations which tend to indicate that the expansion of the universe is presently undergoing an acceleration. Models of fundamental physics which address these issues are discussed. 1
Cosmological constant problem and longdistance modifications of
, 2004
"... We construct the covariant nonlocal action for recently suggested longdistance modifications of gravity theory motivated by the cosmological constant and cosmological acceleration problems. This construction is based on the special nonlocal form of the EinsteinHilbert action explicitly revealing t ..."
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We construct the covariant nonlocal action for recently suggested longdistance modifications of gravity theory motivated by the cosmological constant and cosmological acceleration problems. This construction is based on the special nonlocal form of the EinsteinHilbert action explicitly revealing
Brane World Scenarios and the Cosmological Constant
, 2000
"... Brane world scenarios offer a way of ensuring that a Poincare invariant four dimensional world can emerge, without fine tuning, as a solution to the equations of motion of an effective action. We discuss the different ways in which this happens, and point out that the underlying reason is that there ..."
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Cited by 1 (0 self)
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is that there is a contribution to the effective cosmological constant which is a constant of integration, that maybe adjusted to ensure a flat space solution. Basically this is an old idea revived in a new context and we speculate that there may be string scenarios that provide a concrete realization of it. Finally
Results 1  10
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1,578