We consider a scale invariant extension of the standard model (SM) with a combined breaking of conformal and electroweak symmetry in a strongly interacting hidden SU (n c ) gauge sector with n f vector-like hidden fermions. The (pseudo) Nambu-Goldstone bosons that arise due to dynamical chiral symmetry breaking are dark matter (DM) candidates. We focus on n f = n c = 3, where SU (3) is the largest symmetry group of hidden flavor which can be explicitly broken into either U (1) × U (1) or SU (2) × U (1). We study DM properties and discuss consistent parameter space for each case. Because of different mechanisms of DM annihilation the consistent parameter space in the case of SU (2) × U (1) is significantly different from that of SU (3) if the hidden fermions have a SM U (1) Y charge of O(1).

Drastic changes in the early Universe such as first-order phase transition can produce a stochastic gravitational wave (GW) background. We investigate the testability of a scale invariant extension of the standard model (SM) using the GW background produced by the chiral phase transition in a strongly interacting QCD-like hidden sector, which, via a SM singlet real scalar mediator, triggers the electroweak phase transition. Using the Nambu-Jona-Lasinio method in a mean field approximation we estimate the GW signal and find that it can be tested by future space-based detectors.

Loss of contrast sensitivity was predominantly due to BLS and HOA in eyes with NC and FLS and HOA in eyes with CC. Higher-order aberrations, FLS, and BLS, variables that are obtained objectively, can be used to predict quantitatively the visual deterioration in cataractous eyes.

To understand paleoenvironmental changes for the central Qinghai‐Tibetan plateau, we analyzed stable isotopes of oxygen and carbon from calcium carbonates in a bottom sediment core collected from Siling‐Co (lake). Five conventional and two TAMS 14C dates indicate that the core recovered sediments of the last 14,000 years. Calcium carbonates in the sediments seem to be primary carbonates precipitated chemically in the lake, and not clastic particles from limestones distributed around the lake, because of large variation of isotopic ratios, isotopic covariance since 6,000 yr BP and similarity between dates from total calcium carbonates and organic carbon. Their isotopic composition therefore reflects that of the lake water. We present the following paleoenvironmental history over the last 14,000 years in the central part of the plateau, from secular variations of δ18O, δ13C and CaCO3 content throughout the core: (1) Desiccation was dominant during the latter part of the Last Glacial stage (14,000 to 11,000 yr BP). (2) The Last Glacial stage abruptly terminated at 11,000 yr BP. (3) A temperate and stable climate was dominant from 11,000 to 5,000 yr BP. (4) Climatic conditions fluctuated from 5,000 to the present, including two strong desiccation periods (5,000 to 4,000 yr BP and 3,000 to 2,000 yr BP) and an intermediate period of heavy rainfall (4,000 to 3,000 yr BP). This period is also characterized by a covariant O and C isotopic trend.

Purpose This paper aims to investigate the combined effect of economic policy uncertainty (EPU) and the firm life cycle on the degree of accrual-based earnings management of publicly traded companies in the USA and Brazilian stock markets. Design/methodology/approach The EPU index used was the one developed by Baker et al. (2016), the Kothari et al. (2005) model was used in the main analysis to obtain the discretionary accruals and the classification of firms into different life cycles was based on the Dickinson (2011) approach, which relies on the sign of operating, investment and financing cash flows. The methodology includes correlation matrix and panel regression with fixed effects. Findings The overall results for the USA sample suggest that economic policy uncertainty does have a heterogeneous influence on the firms’ accrual earnings management conditional on their life cycle where firms in the introduction, growth and decline stages decrease this practice when policy uncertainty increases. For the Brazilian case, in general, there is no combined effect between these variables. These contrasting findings can be associated with either the different underlying characteristics of both stock markets or the reduced sample size for the emerging market analyzed. Originality/value This research contributes to the earnings management literature examining how policy uncertainty is related to accruals manipulation under different life cycle stages and institutional environments. It is also one of the first studies to explore this conditioning effect.