Journal of Cosmology and Astroparticle Physics最新文献_第8页

Kick it like DESI: PNGB quintessence with a dynamically generated initial velocity

IF 6.4 2区物理与天体物理

Journal of Cosmology and Astroparticle Physics Pub Date : 2025-03-07 DOI: 10.1088/1475-7516/2025/03/015

Maximilian Berbig

{"title":"Kick it like DESI: PNGB quintessence with a dynamically generated initial velocity","authors":"Maximilian Berbig","doi":"10.1088/1475-7516/2025/03/015","DOIUrl":"https://doi.org/10.1088/1475-7516/2025/03/015","url":null,"abstract":"Motivated by the hint for time-dependent dynamical dark energy from an analysis of the DESI Baryon Accoustic Oscillation (BAO) data together with information from the Cosmic Microwave Background (CMB) and Supernovae (SN), we relax the assumption of a vanishing initial velocity for a quintessence field. In particular we focus on pseudo-Nambu-Goldstone-Boson (PNGB) quintessence in the form of an axion like particle, that can arise as the phase of a complex scalar and could possess derivative couplings to fermions or topological couplings to abelian gauge fields, without upsetting the necessary flatness of its potential. We discuss mechanisms from the aforementioned interactions for sourcing an initial axion field velocity θ̇i at redshifts 3 ≤ z ≤ 10, that will “kick” it into motion. Driven by this initial velocity the axion will first roll up in its potential, similar to “freezing” dark energy. After it has reached the pinnacle of its trajectory, it will start to roll down, and behave as “thawing” quintessence. As a proof of concept we undertake a combined fit to BAO, SN and CMB data at the background level. We find that a scenario with θ̇i = 𝒪(1) ma, where ma is the axion mass, is slightly preferred over both ΛCDM and the conventional “thawing” quintessence with θ̇i = 0. The best fit points for this case exhibit transplanckian decay constants and very flat potentials, which both are in tension with conjectures from string theory.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"30 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143569488","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Stochastic inflation and non-perturbative power spectrum beyond slow roll

IF 6.4 2区物理与天体物理

Journal of Cosmology and Astroparticle Physics Pub Date : 2025-03-07 DOI: 10.1088/1475-7516/2025/03/017

Devanshu Sharma

引用次数: 0

The mass effect — variations of the electron mass and their impact on cosmology

IF 6.4 2区物理与天体物理

Journal of Cosmology and Astroparticle Physics Pub Date : 2025-03-06 DOI: 10.1088/1475-7516/2025/03/004

Nils Schöneberg and Léo Vacher

引用次数: 0

From WIMPs to FIMPs: impact of early matter domination

IF 6.4 2区物理与天体物理

Journal of Cosmology and Astroparticle Physics Pub Date : 2025-03-06 DOI: 10.1088/1475-7516/2025/03/003

Javier Silva-Malpartida, Nicolás Bernal, Joel Jones-Pérez and Roberto A. Lineros

引用次数: 0

The impact of large-scale galaxy clustering on the variance of the Hellings-Downs correlation: theoretical framework

IF 6.4 2区物理与天体物理

Journal of Cosmology and Astroparticle Physics Pub Date : 2025-03-06 DOI: 10.1088/1475-7516/2025/03/011

Nastassia Grimm, Martin Pijnenburg, Giulia Cusin and Camille Bonvin

{"title":"The impact of large-scale galaxy clustering on the variance of the Hellings-Downs correlation: theoretical framework","authors":"Nastassia Grimm, Martin Pijnenburg, Giulia Cusin and Camille Bonvin","doi":"10.1088/1475-7516/2025/03/011","DOIUrl":"https://doi.org/10.1088/1475-7516/2025/03/011","url":null,"abstract":"While pulsar timing array experiments have recently found evidence for the existence of a stochastic gravitational wave (GW) background, its origin is still unclear. If this background is of astrophysical origin, we expect the distribution of GW sources to follow the one of galaxies. Since galaxies are not perfectly isotropically distributed at large scales, but follow the cosmological large-scale structure, this would lead to an intrinsic anisotropy in the distribution of GW sources. In this work, we develop a formalism to account for this anisotropy, by considering a Gaussian ensemble of sources in each realization of the universe and then taking ensemble averages over all such realizations. We find that large-scale galaxy clustering has no impact on the expectation value of pulsar timing residual correlations, described by the Hellings-Downs curve. However, it introduces a new contribution to the variance of the Hellings-Downs correlation. Hence, the anisotropic distribution of sources contributes to the amount by which the measurements of pulsar timing residual correlations, in our single realization of the universe, may differ from the Hellings-Downs curve.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"44 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143560808","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Unveiling V modes: enhancing CMB sensitivity to BSM physics with a non-ideal half-wave plate

IF 6.4 2区物理与天体物理

Journal of Cosmology and Astroparticle Physics Pub Date : 2025-03-06 DOI: 10.1088/1475-7516/2025/03/009

N. Raffuzzi, M. Lembo, S. Giardiello, M. Gerbino, M. Lattanzi, P. Natoli and L. Pagano

{"title":"Unveiling V modes: enhancing CMB sensitivity to BSM physics with a non-ideal half-wave plate","authors":"N. Raffuzzi, M. Lembo, S. Giardiello, M. Gerbino, M. Lattanzi, P. Natoli and L. Pagano","doi":"10.1088/1475-7516/2025/03/009","DOIUrl":"https://doi.org/10.1088/1475-7516/2025/03/009","url":null,"abstract":"V-mode polarization of the cosmic microwave background is expected to be vanishingly small in the ΛCDM model and, hence, usually ignored. Nonetheless, several astrophysical effects, as well as beyond standard model physics could produce it at a detectable level. A realistic half-wave plate — an optical element commonly used in CMB experiments to modulate the polarized signal — can provide sensitivity to V modes without significantly spoiling that to linear polarization. We assess this sensitivity for some new-generation CMB experiments, such as the LiteBIRD satellite, the ground-based Simons Observatory and a CMB-S4-like experiment. We forecast the efficiency of these experiments to constrain the phenomenology of certain classes of BSM models inducing mixing of linear polarization states and generation of V modes in the CMB. We find that new-generation experiments can improve current limits by 1-to-3 orders of magnitude, depending on the data combination. The inclusion of V-mode information dramatically boosts the sensitivity to these BSM models.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"70 9 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143560807","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Quantum gravitational hair in gravastars and observational tests

IF 6.4 2区物理与天体物理

Journal of Cosmology and Astroparticle Physics Pub Date : 2025-03-06 DOI: 10.1088/1475-7516/2025/03/005

Italo Perrucci, Folkert Kuipers and Roberto Casadio

引用次数: 0

Loosely bound composite dark matter

IF 6.4 2区物理与天体物理

Journal of Cosmology and Astroparticle Physics Pub Date : 2025-03-06 DOI: 10.1088/1475-7516/2025/03/013

Javier F. Acevedo, Yilda Boukhtouchen, Joseph Bramante, Christopher Cappiello, Gopolang Mohlabeng and Narayani Tyagi

引用次数: 0

Kinetic field theory: effects of modified gravity theories with screening mechanisms on non-linear cosmic density fluctuations

IF 6.4 2区物理与天体物理

Journal of Cosmology and Astroparticle Physics Pub Date : 2025-03-06 DOI: 10.1088/1475-7516/2025/03/008

A. Oestreicher, H. Saxena, N. Reinhardt, E. Kozlikin, J. Dombrowski and M. Bartelmann

{"title":"Kinetic field theory: effects of modified gravity theories with screening mechanisms on non-linear cosmic density fluctuations","authors":"A. Oestreicher, H. Saxena, N. Reinhardt, E. Kozlikin, J. Dombrowski and M. Bartelmann","doi":"10.1088/1475-7516/2025/03/008","DOIUrl":"https://doi.org/10.1088/1475-7516/2025/03/008","url":null,"abstract":"In a mean-field approximation within Kinetic Field Theory, it is possible to derive an accurate analytic expression for the power spectrum of present-day non-linear cosmic density fluctuations. It depends on the theory of gravity and the cosmological model via the expansion function of the background space-time, the growth factor derived from it, and the gravitational coupling strength, which may deviate from Newton's constant in a manner depending on time and spatial scale. In earlier work [1], we introduced a functional Taylor expansion around general relativity and the cosmological standard model to derive the effects of a wide class of modified-gravity theories on the non-linear power spectrum, assuming that such effects need to be small given the general success of the standard model. Here, we extend this class towards theories with small-scale screening, modeling screening effects by a suitably flexible interpolating function. We compare the Taylor expansion with full mean-field solutions and find good agreement where expected. We find typical relative enhancements of the non-linear power spectrum between a few and a few ten per cent in a broad range of wave numbers between k ≳ 0.1-10 h Mpc, in good qualitative agreement with results of numerical simulations. Taking nDGP gravity as a quantitative example we compare our results to N-body simulations and find percent-level agreement for wavenumbers k ≲ 2 h Mpc-1, if the scale where screening sets in, k*, is adapted appropriately. This extends the application of our analytic approach to non-linear cosmic structure formation to essentially all classes of modified-gravity theories.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"49 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143561278","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Cosmic recombination in the presence of primordial magnetic fields

IF 6.4 2区物理与天体物理

Journal of Cosmology and Astroparticle Physics Pub Date : 2025-03-06 DOI: 10.1088/1475-7516/2025/03/012

Karsten Jedamzik, Tom Abel and Yacine Ali-Haïmoud

{"title":"Cosmic recombination in the presence of primordial magnetic fields","authors":"Karsten Jedamzik, Tom Abel and Yacine Ali-Haïmoud","doi":"10.1088/1475-7516/2025/03/012","DOIUrl":"https://doi.org/10.1088/1475-7516/2025/03/012","url":null,"abstract":"Primordial magnetic fields (PMFs) may explain observations of magnetic fields on extragalactic scales. They are most cleanly constrained by measurements of cosmic microwave background radiation (CMB) anisotropies. Their effects on cosmic recombination may even be at the heart of the resolution of the Hubble tension. We present the most detailed analysis of the effects of PMFs on cosmic recombination to date. To this end we extend the public magneto-hydrodynamic code ENZO with a new cosmic recombination routine, Monte-Carlo simulations of Lyman-α photon transport, and a Compton drag term in the baryon momentum equation. The resulting code allows us, for the first time, to realistically predict the impact of PMFs on the cosmic ionization history and the clumping of baryons during cosmic recombination. Our results identify the importance of mixing of Lyman-α photons between overdense- and underdense- regions for small PMF strength. This mixing speeds up recombination beyond the speed-up due to clumping. We also investigate the effects of pecuilar flows on the recombination rate and find it to be small for small PMF strengths. For non-helical PMFs with a Batchelor spectrum we find a surprising dependency of results on ultra-violet magnetic modes. We further show that the increase in the ionization fraction at low redshift by hydrodynamic baryon heating due to PMF dissipation is completely compensated by the faster recombination from baryon clumping. The present study shall serve as a theoretical foundation for a future precise comparison of recombination with PMFs to CMB data.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"11 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143561281","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0