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marcus

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In ordinary GR geometry, the Higgs field cannot play the rôle of the inflaton, so to imagine inflation one has to introduce some exotic field that is not part of the Standard Model. Something completely made up must be introduced to make it work.

Not so in the context of non-commutative geometry (NGC) say William Nelson and Mairi Sakellariadou.

==quote==

...within the noncommutative geometry approach to unifying gravity and the standard model, it is possible to have an epoch of inﬂation sourced by the dynamics of the Higgs ﬁeld.

In addition, this type of noncommutative inﬂation could have speciﬁc consequences that would discriminate it from alternative models. In particular, since the theory contains all of the standard model ﬁelds, along with their couplings to the Higgs ﬁeld, which in this scenario plays the rôle of the inﬂaton, a quantitative investigation of reheating should be possible. More signiﬁcantly, the cosmological evolution equations for inhomogeneous perturbations diﬀers from those of the standard Friedmann-Lemaître-Robertson-Walker cosmology [7]. This raises the possibility that signatures of this noncommutative inﬂation could be contained within the cosmic microwave background power spectrum.

==endquote==

http://arxiv.org/abs/0903.1520

William Nelson, Mairi Sakellariadou

3 pages

(Submitted on 9 Mar 2009)

"The possibility of having an inflationary epoch within a noncommutative geometry approach to unifying gravity and the standard model is demonstrated. This inflationary phase occurs without the need to introduce 'ad hoc' additional fields or potentials, rather it is a consequence of a nonminimal coupling between the geometry and the Higgs field."

======================

Nelson and Sakellariadou explain why the Higgs field does not work

==quote==

Unfortunately, it has proved diﬃcult to naturally embed inﬂation within an underlying fundamental theory. Inﬂation most naturally occurs when the dynamics of the universe are dominated by the evolution of a scalar ﬁeld, the inﬂaton, slowly rolling in its potential; the form of the potential deﬁnes the type of the inﬂationary model.

There is only one scalar ﬁeld within the standard model of particle physics, the Higgs ﬁeld, and it is naturally hoped that this could play the rôle of the inﬂaton. However, it has been shown[4] that inorder for the Higgs ﬁeld to produce the correct amplitude of density perturbations,

==endquote==

We already have an earlier paper by the same authors about NCG cosmology.

Not so in the context of non-commutative geometry (NGC) say William Nelson and Mairi Sakellariadou.

==quote==

...within the noncommutative geometry approach to unifying gravity and the standard model, it is possible to have an epoch of inﬂation sourced by the dynamics of the Higgs ﬁeld.

In addition, this type of noncommutative inﬂation could have speciﬁc consequences that would discriminate it from alternative models. In particular, since the theory contains all of the standard model ﬁelds, along with their couplings to the Higgs ﬁeld, which in this scenario plays the rôle of the inﬂaton, a quantitative investigation of reheating should be possible. More signiﬁcantly, the cosmological evolution equations for inhomogeneous perturbations diﬀers from those of the standard Friedmann-Lemaître-Robertson-Walker cosmology [7]. This raises the possibility that signatures of this noncommutative inﬂation could be contained within the cosmic microwave background power spectrum.

==endquote==

http://arxiv.org/abs/0903.1520

**Natural inflation mechanism in asymptotic noncommutative geometry**William Nelson, Mairi Sakellariadou

3 pages

(Submitted on 9 Mar 2009)

"The possibility of having an inflationary epoch within a noncommutative geometry approach to unifying gravity and the standard model is demonstrated. This inflationary phase occurs without the need to introduce 'ad hoc' additional fields or potentials, rather it is a consequence of a nonminimal coupling between the geometry and the Higgs field."

======================

Nelson and Sakellariadou explain why the Higgs field does not work

==quote==

Unfortunately, it has proved diﬃcult to naturally embed inﬂation within an underlying fundamental theory. Inﬂation most naturally occurs when the dynamics of the universe are dominated by the evolution of a scalar ﬁeld, the inﬂaton, slowly rolling in its potential; the form of the potential deﬁnes the type of the inﬂationary model.

There is only one scalar ﬁeld within the standard model of particle physics, the Higgs ﬁeld, and it is naturally hoped that this could play the rôle of the inﬂaton. However, it has been shown[4] that inorder for the Higgs ﬁeld to produce the correct amplitude of density perturbations,

**its mass would have to be some 11 orders of magnitude higher**than the one required by particle physics. This conclusion was however reached using general relativistic cosmology and here we re-examine the calculation in the context of cosmological noncommutative geometry[5, 6, 7].==endquote==

We already have an earlier paper by the same authors about NCG cosmology.

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