Higgs-otic inflation and string theory

We propose that inflation is driven by a (complex) neutral Higgs of the MSSM extension of the SM, in a chaotic-like inflation setting. The SUSY breaking soft term masses are of order 10 12 − 10 13 GeV, which is identified with the inflaton mass scale and is just enough to stabilise the SM Higgs potential. The fine-tuned SM Higgs has then a mass around 126 GeV, in agreement with LHC results. We point out that the required large field excursions of chaotic inflation may be realised in string theory with the (complex) inflaton/Higgs identified with a continuous Wilson line or D-brane position. We show specific examples and study in detail a IIB orientifold with D7-branes at singularities, with SM gauge group and MSSM Higgs sector. In this case the inflaton/Higgs fields correspond to D7-brane positions along a two-torus transverse to them. Masses and monodromy are induced by closed string G 3 fluxes, and the inflaton potential can be computed directly from the DBI+CS action. We show how this action sums over Planck suppressed corrections, which amount to a field dependent rescaling of the inflaton fields, leading to a linear potential in the large field regime. We study the evolution of the two components of the Higgs/inflaton and compute the slow-roll parameters for purely adiabatic perturbations. For large regions of initial conditions slow roll inflation occurs and 50-60 efolds are obtained with r > 0.07, testable in forthcoming experiments. Our scheme is economical in the sense that both EWSB and inflation originate in the same sector of the theory, all inflaton couplings are known and reheating occurs efficiently

The inflaton as an MSSM Higgs and open string modulus monodromy inflation

It has been recently pointed out that high scale inflation, as recently hinted by the BICEP2 results, is consistent with the identification of an inflaton mass mI≃1013 GeV with the SUSY breaking scale in an MSSM with a fine-tuned SM Higgs. This identification leads to a Higgs mass mh≃126 GeV , consistent with LHC measurements. Here we propose that this naturally suggests to identify the inflaton with the heavy MSSM Higgs system. The fact that the extrapolated Higgs coupling λSM≃0 at scales below the Planck scale suggests the Higgs degrees of freedom could be associated with a Wilson line or D-brane position modulus in string theory. The Higgs system then has a shift symmetry and an N=2 structure which guarantees that its potential has an approximate quadratic chaotic inflation form. These moduli in string compactifications, being compact, allow for trans-Planckian inflaton field range analogous to a version of monodromy inflation

BICEP2, the Higgs mass and the SUSY-breaking scale

Recent BICEP2 results on CMB polarisation B-modes suggest a high value for the inflation scale <math altimg="si1.gif" xmlns="http://www.w3.org/1998/Math/MathML"><msubsup><mrow><mi>V</mi></mrow><mrow><mn>0</mn></mrow><mrow><mn>1</mn><mo stretchy="false">/</mo><mn>4</mn></mrow></msubsup><mo>≃</mo><msup><mrow><mn>10</mn></mrow><mrow><mn>16</mn></mrow></msup><mtext> </mtext><mtext>GeV</mtext></math> , giving experimental evidence for a physical scale in between the EW scale and the Planck mass. We propose that this new high scale could be interpreted as evidence for a high SUSY breaking scale with MSSM sparticles with masses of order <math altimg="si2.gif" xmlns="http://www.w3.org/1998/Math/MathML"><msub><mrow><mi>M</mi></mrow><mrow><mi>s</mi><mi>s</mi></mrow></msub><mo>≃</mo><msup><mrow><mn>10</mn></mrow><mrow><mn>12</mn></mrow></msup><mtext>–</mtext><msup><mrow><mn>10</mn></mrow><mrow><mn>13</mn></mrow></msup><mtext> </mtext><mtext>GeV</mtext></math> . We show that such a large value for <math altimg="si3.gif" xmlns="http://www.w3.org/1998/Math/MathML"><msub><mrow><mi>M</mi></mrow><mrow><mi>s</mi><mi>s</mi></mrow></msub></math> is consistent with a Higgs mass around 126 GeV. We briefly discuss some possible particle physics implications of this assumption

Special points of inflation in flux compactifications

We study the realization of axion inflation models in the complex structure moduli spaces of Calabi–Yau threefolds and fourfolds. The axions arise close to special points of these moduli spaces that admit discrete monodromy symmetries of infinite order. Examples include the large complex structure point and conifold point, but can be of more general nature. In Type IIB and F-theory compactifications the geometric axions receive a scalar potential from a flux-induced superpotential. We find toy variants of various inflationary potentials including the ones for natural inflation of one or multiple axions, or axion monodromy inflation with polynomial potential. Interesting examples are also given by mirror geometries of torus fibrations with Mordell–Weil group of rank N−1 or an N -section, which admit an axion if N>3