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A pseudo-scalar inflaton field can have interesting phenomenological signatures associated with parity violation. The existing analyses of these signatures typically assume statistical isotropy. In the present work we instead investigate…

Cosmology and Nongalactic Astrophysics · Physics 2015-01-22 Nicola Bartolo , Sabino Matarrese , Marco Peloso , Maresuke Shiraishi

Under the existence of chiral non-Gaussian sources during inflation, the trispectrum of primordial curvature perturbations can break parity. We examine signatures of the induced trispectrum of the cosmic microwave background (CMB)…

Cosmology and Nongalactic Astrophysics · Physics 2016-10-06 Maresuke Shiraishi

We study the statistical descriptors for some cosmological inflationary models that allow us to get large levels of non-gaussianity and violations of statistical isotropy. Basically, we study two different class of models: a model that…

Cosmology and Nongalactic Astrophysics · Physics 2010-05-05 Cesar A. Valenzuela-Toledo

We suggest the universe is Finslerian in the stage of inflation. The Finslerian background spacetime breaks rotational symmetry and induces parity violation. The primordial power spectrum is given for quantum fluctuation of the inflation…

General Relativity and Quantum Cosmology · Physics 2015-02-16 Xin Li , Sai Wang , Zhe Chang

We show that inflationary models with broken rotational invariance generate testable off-diagonal signatures in the correlation between the $\mu$-type distortion and temperature fluctuations of the cosmic microwave background. More…

Cosmology and Nongalactic Astrophysics · Physics 2015-10-07 Maresuke Shiraishi , Michele Liguori , Nicola Bartolo , Sabino Matarrese

Although the cosmic microwave background (CMB) is largely understood to be homogeneous and isotropic, the CMB angular power spectra present anomalies that seem to break down parity symmetry at large angular scales. We argue that the…

General Relativity and Quantum Cosmology · Physics 2024-11-12 K. Sravan Kumar , João Marto

The space of inflationary models is vast, containing wide varieties of mechanisms, symmetries, and spectra of particles. Consequently, the space of observational signatures is similarly complex. Hence, it is natural to look for boundaries…

High Energy Physics - Theory · Physics 2020-10-29 Daniel Green , Enrico Pajer

We investigate parity-violating signatures of temperature and polarization bispectra of the cosmic microwave background (CMB) in an inflationary model where a rolling pseudoscalar produces large equilateral tensor non-Gaussianity. By a…

Cosmology and Nongalactic Astrophysics · Physics 2013-11-22 Maresuke Shiraishi , Angelo Ricciardone , Shohei Saga

A suitable coupling of the inflaton phi to a vector kinetic term F^2 gives frozen and scale invariant vector perturbations. We compute the cosmological perturbations zeta that result from such coupling by taking into account the classical…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 Nicola Bartolo , Sabino Matarrese , Marco Peloso , Angelo Ricciardone

Cosmological inflation remains to be a unique mechanism of generation of plausible initial conditions in the early universe. In particular, it generates the primordial quasiclassical perturbations with power spectrum determined by the…

Cosmology and Nongalactic Astrophysics · Physics 2010-03-23 Yuri Shtanov

We study the most general contributions due to scalar field perturbations, vector field perturbations, and anisotropic expansion to the generation of statistical anisotropy in the primordial curvature perturbation \zeta. Such a study is…

Cosmology and Nongalactic Astrophysics · Physics 2013-07-25 L. Gabriel Gomez , Yeinzon Rodriguez

We study temperature and polarization anisotropies of the cosmic microwave background (CMB) radiation sourced from primordial cross-bispectra between metric perturbations and vector fields, which are generated from the inflation model where…

Cosmology and Nongalactic Astrophysics · Physics 2012-12-18 Maresuke Shiraishi , Shohei Saga , Shuichiro Yokoyama

We consider a model of inflation consisting a triplet of $U(1)$ vector fields with the parity violating interaction which is non-minimally coupled to inflaton. The vector field sector enjoys global $O(3)$ symmetry which admits isotropic…

Cosmology and Nongalactic Astrophysics · Physics 2020-12-16 Mohammad Ali Gorji , Seyed Ali Hosseini Mansoori , Hassan Firouzjahi

Parity-violating interactions are ubiquitous phenomena in particle physics. If they are significant during cosmic inflation, they can leave imprints on primordial perturbations and be observed in correlation functions of galaxy surveys.…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-21 Yunjia Bao , Lian-Tao Wang , Zhong-Zhi Xianyu , Yi-Ming Zhong

We investigate the impact of statistical inhomogeneity and anisotropy in primordial scalar perturbations on the scalar-induced gravitational waves (SIGW). Assuming inflationary quantum fluctuations originate from a coherent state, the…

Cosmology and Nongalactic Astrophysics · Physics 2026-01-08 Dipayan Mukherjee , H. V. Ragavendra , Shiv K. Sethi

This thesis is centered on three main subjects within the theory of inflation and cosmological perturbations: loop corrections to the power spectrum of curvature fluctuations generated during inflation; evolution of cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2010-04-13 Emanuela Dimastrogiovanni

We consider a primordial SU(2) vector multiplet during inflation in models where quantum fluctuations of vector fields are involved in producing the curvature perturbation. Recently, a lot of attention has been paid to models populated by…

Cosmology and Nongalactic Astrophysics · Physics 2011-07-13 Nicola Bartolo , Emanuela Dimastrogiovanni , Sabino Matarrese , Antonio Riotto

We compute the phenomenological signatures of a model (Watanabe et al' 09) of anisotropic inflation driven by a scalar and a vector field. The action for the vector is U(1) invariant, and the model is free of ghost instabilities. A suitable…

Cosmology and Nongalactic Astrophysics · Physics 2010-04-08 A. E. Gumrukcuoglu , Burak Himmetoglu , Marco Peloso

We study the cosmology on the Friedmann-Lemaitre-Robertson-Walker background in scalar-vector-tensor theories with a broken $U(1)$ gauge symmetry. For parity-invariant interactions arising in scalar-vector-tensor theories with second-order…

General Relativity and Quantum Cosmology · Physics 2018-07-27 Lavinia Heisenberg , Ryotaro Kase , Shinji Tsujikawa

Recently, possible hints of parity violation have been observed in the connected galaxy four-point correlation function. Although the true origin of the signal from the analysis has been debated, should they have a physical origin, they…

Cosmology and Nongalactic Astrophysics · Physics 2025-07-22 Tommaso Moretti , Nicola Bartolo , Alessandro Greco
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