Instability of the invisible axion

Ghigna, Sebastiano; Lusignoli, M.; Roncadelli, M.

doi:10.1016/0370-2693(92)90019-z

Cited by 155 publications

(140 citation statements)

References 25 publications

Supporting

Mentioning

140

Contrasting

Order By: Relevance

“…As far as the latter case is concerned, it is important to note that the possibly inherent domain wall problem can be circumvented if the PQ symmetry is only a low energy remnant of an exact discrete symmetry, so that Planck scale suppressed PQ violating operators -which have been argued to be induced in any case by quantum gravity effects [84][85][86][87], and which render string-wall systems with N DW > 1 unstable -occur at dimension ten 14 [69]. In this case, the preferred mass range for dark matter is a bit higher than the one singled out in the post-inflationary N DW = 1 scenario.…”

Section: Jhep02(2018)103mentioning

confidence: 99%

Axion predictions in SO(10) × U(1)PQ models

Ernst

Ringwald

Tamarit

2018

J. High Energ. Phys.

View full text Add to dashboard Cite

Non-supersymmetric Grand Unified SO(10) × U(1) PQ models have all the ingredients to solve several fundamental problems of particle physics and cosmologyneutrino masses and mixing, baryogenesis, the non-observation of strong CP violation, dark matter, inflation -in one stroke. The axion -the pseudo Nambu-Goldstone boson arising from the spontaneous breaking of the U(1) PQ Peccei-Quinn symmetry -is the prime dark matter candidate in this setup. We determine the axion mass and the low energy couplings of the axion to the Standard Model particles, in terms of the relevant gauge symmetry breaking scales. We work out the constraints imposed on the latter by gauge coupling unification. We discuss the cosmological and phenomenological implications.

show abstract

Section: Jhep02(2018)103mentioning

confidence: 99%

Axion predictions in SO(10) × U(1)PQ models

Ernst

Ringwald

Tamarit

2018

J. High Energ. Phys.

View full text Add to dashboard Cite

show abstract

“…A set of independent equations is provided by either one of (21) and by (22). Equivalently, one can solve the two equations (21), but then eq.…”

Section: Introductionmentioning

confidence: 99%

“…Equivalently, one can solve the two equations (21), but then eq. (22) has to be imposed as an initial condition. Whatever the choice, the background evolution is completely determined by the initial valuesQ in and∂Q in (for a flat universe, the normalization of the scale factor is arbitrary, and we set a in = 1).…”

Section: Introductionmentioning

confidence: 99%

Gauge-flation confronted with Planck

Namba¹,

Dimastrogiovanni²,

Peloso³

2013

J. Cosmol. Astropart. Phys.

110

View full text Add to dashboard Cite

Gauge-flation is a recently proposed model in which inflation is driven solely by a non-Abelian gauge field thanks to a specific higher order derivative operator. The nature of the operator is such that it does not introduce ghosts. We compute the cosmological scalar and tensor perturbations for this model, improving over an existing computation. We then confront these results with the Planck data. The model is characterized by the quantity γ ≡H 2 (where g is the gauge coupling constant, Q the vector vev, and H the Hubble rate). For γ < 2, the scalar perturbations show a strong tachyonic instability. In the stable region, the scalar power spectrum n s is too low at small γ, while the tensor-to-scalar ratio r is too high at large γ. No value of γ leads to acceptable values for n s and r, and so the model is ruled out by the CMB data. The same behavior with γ was obtained in Chromo-natural inflation, a model in which inflation is driven by a pseudo-scalar coupled to a non-Abelian gauge field. When the pseudo-scalar can be integrated out, one recovers the model of Gauge-flation plus corrections. It was shown that this identification is very accurate at the background level, but differences emerged in the literature concerning the perturbations of the two models. On the contrary, our results show that the analogy between the two models continues to be accurate also at the perturbative level.

show abstract

“…For instance, Planck-suppressed higher dimensional operators can induce sufficiently small energy bias between N degenerate minima. It should be noted that such Planck-suppressed operators induce a large CP-violating effect which spoils the original PQ solution to the strong CP problem [88][89][90][91][92][93], and that the dimension of those operators must be sufficiently high in order to avoid the experimental limit on the CP violation [94]. These kinds of higher dimensional operators naturally arise if we assume that the PQ symmetry is an accidental symmetry of an exact discrete symmetry [95][96][97].…”

Section: Axion Modelsmentioning

confidence: 99%

A Review of Gravitational Waves from Cosmic Domain Walls

2017

View full text Add to dashboard Cite

Abstract:In this contribution, we discuss the cosmological scenario where unstable domain walls are formed in the early universe and their late-time annihilation produces a significant amount of gravitational waves. After describing cosmological constraints on long-lived domain walls, we estimate the typical amplitude and frequency of gravitational waves observed today. We also review possible extensions of the standard model of particle physics that predict the formation of unstable domain walls and can be probed by observation of relic gravitational waves. It is shown that recent results of pulser timing arrays and direct detection experiments partially exclude the relevant parameter space, and that a much wider parameter space can be covered by the next generation of gravitational wave observatories.

show abstract

Instability of the invisible axion

Cited by 155 publications

References 25 publications

Axion predictions in SO(10) × U(1)PQ models

Axion predictions in SO(10) × U(1)PQ models

Gauge-flation confronted with Planck

A Review of Gravitational Waves from Cosmic Domain Walls

Contact Info

Product

Resources

About