Our aim in this paper is to extend a work of Sivatski to characteristic 2. More precisely, for F a field of characteristic 2 and a central simple algebra A of exponent 2 that splits over a triquadratic extension of F of separability degree at least 4, we attach a cohomological invariant inv(A) is an element of H23(F)/G, where H23 (F) is the third Kato-Milne cohomology group and G is a subgroup of H23 (F) divisible by the Brauer class of A. As an application, we will relate the decomposability of the algebra in degree 8 to the vanishing of inv(A). Moreover, we will use this invariant to prove some descent results for central simple algebras and quadratic forms over biquadratic extensions. (c) 2026 The Author(s). Published by Elsevier Inc. This is an open access article under the CC BY license (http:// creativecommons.org/licenses/by/4.0/).
Carbazole-based self-assembled monolayers (SAMs) have emerged as promising interfacial materials for inverted (p-i-n) perovskite solar cells owing to their simple synthesis, strong binding affinity toward metal oxides, and potential to enhance charge extraction at the interface. In this work, we systematically investigated the phosphonic-acid-based carbazole SAM MeO-4PACz deposited on FTO and NiO in inverted, ambient air-processed MAPbI3 perovskite solar cells. This work focuses on elucidating the interfacial role of MeO-4PACz which remains less explored in the literature, particularly under ambient air processing conditions. We elucidate the influence of this SAM on NiO and FTO surface chemistry, energy level alignment, carrier extraction dynamics at the HTL/perovskite interface and its effect on the optoelectronic properties of PSCs. Our results reveal that the incorporation of NiO beneath the MeO-4PACz layer reinforces interfacial coordination bonding, leading to improved perovskite crystallization and enlarged grain size and enhanced film quality. Furthermore, MeO-4PACz SAM anchoring induces a beneficial shift in the electrode work function improving energy level alignment, which reduces interfacial trap-assisted recombination at the interface and within the perovskite bulk. The combined NiO/SAM interfacial engineering is therefore shown to be the key factor governing both film growth and charge extraction mechanisms Consequently, the optimized FTO/NiO/MeO-4PACz device achieves a champion power conversion efficiency of 15.16% making a bond of 66.6% relative to non-treated samples (9.1%). This dramatic enhancement of power conversion efficiency results from improved opencircuit voltage, increased fill factor, and reduced hysteresis.
Lagrangian systems subject to fractional damping can be incorporated into a variational framework by doubling the state variables and introducing fractional derivatives. Fractional variational integrators based on backward-differentiation convolution quadrature (BD-FCQ), combined with higher-order Galerkin methods, saturate at second-order accuracy because the multistep structure of BDFCQ does not take into account the internal stages of the Galerkin discretization. The main objective of this paper is to develop fractional variational integrators (FVIs) by combining Runge-Kutta convolution quadrature (RKCQ) for the approximation of fractional derivatives with higher-order Galerkin methods. The RKCQ approach is naturally compatible with such stage-based discretizations and is therefore better suited for the construction of higher-order schemes. We are particularly interested in the CQ based on Lobatto IIIC. Preservation properties such as energy decay, as well as convergence properties, are investigated numerically and proved for second-order schemes. The presented schemes reach 2nd, 4th and 6th order of accuracy. A brief discussion on the midpoint fractional integrator is also included.
PurposeThis study aims to examine the effect of responsible governance on tax avoidance and the moderating effect of corporate social responsibility (CSR), business ethics and green innovation on this relationship.Design/methodology/approachThe authors relied on a sample of 475 ESG index companies from 2013 to 2022, using the feasible generalized least squares (FGLS) method. To test robustness, the authors included an alternative measure of tax avoidance, applied the generalized method of moments (GMM) to address endogeneity, and accounted for the specific impact of the COVID-19 pandemic.FindingsThe results demonstrate that responsible governance significantly reduces tax avoidance. Furthermore, CSR, business ethics and green innovation reinforce this effect, confirming their moderating role.Practical implicationsThe study provides practical advice to managers and policymakers on integrating governance, CSR, business ethics and green innovation to combat tax avoidance.Originality/valueThis study sheds light on the impact of responsible governance on corporate tax avoidance by highlighting the moderating role of CSR and business ethics and green innovation. Although these factors are interrelated, they capture distinct dimensions of corporate responsibility, offering a more comprehensive understanding of governance mechanisms. It also makes a unique contribution by showing that green innovation strengthens this link, which has not been previously studied.
This study uses high-frequency price data to analyze risk connectivity among 15 cryptocurrencies, focusing on moments such as volatility, skewness, kurtosis, and jumps during the pre-COVID-19 era, the COVID-19 epidemic, and Russian-Ukrainian tensions. The results indicate that Ethereum Classic is a major shock transmitter in all periods, and this effect becomes more pronounced during geopolitical crises. In contrast, Stellar, Tezos, and Tron are important shock absorbers, particularly during market volatility. Jump risk analysis confirms the dominance of Ethereum Classic and its capacity to increase spillover risks during crises. For higher-order moments, the findings reveal that Bitcoin, Ethereum, and Dash are significant transmitters of skewness spreads, whereas Dash and Eos are significant transmitters of kurtosis spreads. Jump risk analysis confirms the dominance of Ethereum Classic and its capacity to increase spillover risks during crises. These findings highlight the need for targeted risk management strategies adjusted to cryptocurrency market dynamics.
