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Related papers: Cosmological Constraints on Unparticles as Continu…

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Unparticle cosmology gives an unconventional outlook on the dark sector of cosmology, increasingly challenging $\Lambda\mbox{CDM}$ by $H_0$-tension. This model derives from a finite temperature broken conformal symmetry of radiation,…

Cosmology and Nongalactic Astrophysics · Physics 2023-03-31 Maurice H. P. M. van Putten , Maryam Aghaei Abchouyeh

We use stellar dynamics arguments to constrain the relevant parameters of ungravity inspired models. We show that resulting bounds do constrain the parameters of the theory of unparticles, as far as its energy scale satisfies the condition…

Solar and Stellar Astrophysics · Physics 2009-08-12 O. Bertolami , J. Paramos , P. Santos

We discuss cosmological constraints on a dark scalar particle mixing with the Standard Model Higgs boson. We pay particular attention to the dark scalar production process when the reheating temperature of the Universe is very low, which…

High Energy Physics - Phenomenology · Physics 2022-04-20 Masahiro Ibe , Shin Kobayashi , Yuhei Nakayama , Satoshi Shirai

In unparticle dark matter (unmatter) models the equation of state of the unmatter is given by $p=\rho/(2d_U+1)$, where $d_U$ is the scaling factor. Unmatter with such equations of state would have a significant impact on the expansion…

Astrophysics · Physics 2008-12-18 Yan Gong , Xuelei Chen

It has recently been suggested that a scale invariant "unparticle" sector with a non-trivial infrared fixed point may couple to the Standard Model (SM) via higher dimensional operators. The weakness of such interactions hides the the…

High Energy Physics - Phenomenology · Physics 2008-11-26 Hooman Davoudiasl

We discuss the physical interpretation of unparticles and review the constraints from cosmology. Unparticles may be understood in terms of confined states of a strongly-coupled scale-invariant theory, where scale-invariance implies that the…

High Energy Physics - Phenomenology · Physics 2008-05-20 John McDonald

Unparticle $\U$ with scaling dimension $d_\U$ has peculiar thermal properties due to its unique phase space structure. We find that the equation of state parameter $\omega_\U$, the ratio of pressure to energy density, is given by $1/(2d_\U…

High Energy Physics - Phenomenology · Physics 2009-03-24 Shao-Long Chen , Xiao-Gang He , Xue-Peng Hu , Yi Liao

Unparticles ($\U$) interact weakly with particles. The direct signature of unparticles will be in the form of missing energy. We study constraints on unparticle interactions using totally invisible decay modes of $Z$, vector quarkonia $V$…

High Energy Physics - Phenomenology · Physics 2009-01-06 Shao-Long Chen , Xiao-Gang He , Ho-Chin Tsai

Many extensions of the Standard Model predict large numbers of additional unstable particles whose decays in the early universe are tightly constrained by observational data. For example, the decays of such particles can alter the ratios of…

High Energy Physics - Phenomenology · Physics 2019-02-20 Keith R. Dienes , Jason Kumar , Patrick Stengel , Brooks Thomas

We have investigated the impact of long-range forces induced by unparticle operators of scalar, vector and tensor nature coupled to fermions in the interpretation of solar neutrinos and KamLAND data. If the unparticle couplings to the…

High Energy Physics - Phenomenology · Physics 2008-11-26 M. C. Gonzalez-Garcia , P. C. Holanda , R. Zukanovich Funchal

If scale invariance is exact, unparticles are unlikely to be probed in colliders since there are stringent constraints from astrophysics and cosmology. However these constraints are inapplicable if scale invariance is broken at a scale mu…

High Energy Physics - Phenomenology · Physics 2008-11-26 Vernon Barger , Yu Gao , Wai-Yee Keung , Danny Marfatia , V. Nefer Senoguz

A finite vacuum energy density implies the existence of a UV scale for gravitational modes. This gives a phenomenological scale to the dynamical equations governing the cosmological expansion that must satisfy constraints consistent with…

Astrophysics · Physics 2007-05-23 James Lindesay

A limiting temperature of a species can cause the Universe to asymptote to it yielding a deSitter (dS) phase due to macroscopic emergent behavior. The limiting temperature is generic for theories slightly shifted from their conformal point.…

High Energy Physics - Phenomenology · Physics 2021-07-01 Michal Artymowski , Ido Ben-Dayan , Utkarsh Kumar

SN 1987A observations have been used to place constraints on the interactions between standard model particles and unparticles. In this study we calculate the energy loss from the supernovae core through scalar, pseudo scalar, vector,…

High Energy Physics - Phenomenology · Physics 2008-11-26 Sukanta Dutta , Ashok Goyal

We study cosmological models involving scalar fields coupled to radiation and discuss their effect on the redshift evolution of the cosmic microwave background temperature, focusing on links with varying fundamental constants and dynamical…

Cosmology and Nongalactic Astrophysics · Physics 2014-07-15 A. Avgoustidis , C. J. A. P. Martins , A. M. R. V. L. Monteiro , P. E. Vielzeuf , G. Luzzi

A new U(1) gauge symmetry is the simplest extension of the Standard Model and has various theoretical and phenomenological motivations. In this paper, we study the cosmological constraint on the MeV scale dark photon. After the neutrino…

High Energy Physics - Phenomenology · Physics 2020-09-30 Masahiro Ibe , Shin Kobayashi , Yuhei Nakayama , Satoshi Shirai

We investigate constraints on scalar dark matter (DM) by analyzing the Lyman-alpha forest, which probes structure formation at medium and small scales, and also by studying its cosmological consequences at high and low redshift. For scalar…

Cosmology and Nongalactic Astrophysics · Physics 2017-12-18 Takeshi Kobayashi , Riccardo Murgia , Andrea De Simone , Vid Iršič , Matteo Viel

We present the first cosmological constraint on dark matter scattering with protons in the early Universe for the entire range of dark matter masses between 1 keV and 1 TeV. This constraint is derived from the Planck measurements of the…

Cosmology and Nongalactic Astrophysics · Physics 2018-09-05 Vera Gluscevic , Kimberly K. Boddy

We explore the model-independent constraints from cosmology on a dark-matter particle with no prominent standard model interactions that interacts and thermalizes with other particles in a hidden sector. Without specifying detailed…

Cosmology and Nongalactic Astrophysics · Physics 2012-03-29 Subinoy Das , Kris Sigurdson

We discuss an extended model with chiral tensor particles in the Universe. Their direct influence on the Universe dynamics and their characteristic interactions in the hot Universe plasma, considered in previous publications, are briefly…

General Physics · Physics 2019-05-17 D. P. Kirilova , E. M. Chizhov
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