Monoidal Hom-Hopf algebras

Hom-structures (Lie algebras, algebras, coalgebras, Hopf algebras) have been investigated in the literature recently. We study Hom-structures from the point of view of monoidal categories; in particular, we introduce a symmetric monoidal category such that Hom-algebras coincide with algebras in this monoidal category, and similar properties for coalgebras, Hopf algebras and Lie algebras.Comment: 25 pages; extended version: compared to the version that appeared in Comm. Algebra, the Section Preliminary Results and Remarks 5.1 and 6.1 have been adde

Can the insider-outsider theory explain unemployment hysteresis in OCED countries?

The insider-outsider theory has been commonly used to explain the hysteretic behaviour of unemployment. However, there is no empirical evidence about the validity of insiders’ power on explaining the persistence of unemployment. This paper, using panel unit root tests that allow for the presence of covariates, addresses this gap and examines whether the insider-outsider theory, by means of various labour market proxies, can explain the hysteresis hypothesis for the OECD countries over 1960-2013. Our results show that although unemployment rate exhibits a pronounced hysteretic behaviour in OECD countries, this behaviour is reversed once we consider the insider-outsider proxies as covariates. This validates the role of insiders’ power as a key source of unemployment hysteresis

Representations of hom-Lie algebras

In this paper, we study representations of hom-Lie algebras. In particular, the adjoint representation and the trivial representation of hom-Lie algebras are studied in detail. Derivations, deformations, central extensions and derivation extensions of hom-Lie algebras are also studied as an application.Comment: 16 pages, multiplicative and regular hom-Lie algebras are used, Algebra and Representation Theory, 15 (6) (2012), 1081-109

Trends in income inequality

Literature recently highlights that the income inequality has increased in almost all countries since the 1980s, which leads to the following question; is there a secular trend and shift in income inequality of developing and/or advanced countries? We address this question using the Gini coefficient for a sample of 21 advanced and developing countries over 1960-2015. We also assess the inequality gap between developing and advanced countries. We find that the income inequality exhibits negative, mainly in Latin America countries, positive, or trendless behaviours. The Gini coefficient of developing countries also exhibit different behaviours relative to advanced countries. Overall, a secular trend of inequality cannot be identified across advanced and/or developing countries in our sample. Our findings raise some concerns regarding the efficiency of global policies to reduce of among-country inequality, one of the main goals of United Nations for the next 15 years

Ternary q-Virasoro-Witt Hom-Nambu-Lie algebras

In this paper we construct ternary $q$-Virasoro-Witt algebras which $q$-deform the ternary Virasoro-Witt algebras constructed by Curtright, Fairlie and Zachos using $su(1,1)$ enveloping algebra techniques. The ternary Virasoro-Witt algebras constructed by Curtright, Fairlie and Zachos depend on a parameter and are not Nambu-Lie algebras for all but finitely many values of this parameter. For the parameter values for which the ternary Virasoro-Witt algebras are Nambu-Lie, the corresponding ternary $q$-Virasoro-Witt algebras constructed in this article are also Hom-Nambu-Lie because they are obtained from the ternary Nambu-Lie algebras using the composition method. For other parameter values this composition method does not yield Hom-Nambu Lie algebra structure for $q$-Virasoro-Witt algebras. We show however, using a different construction, that the ternary Virasoro-Witt algebras of Curtright, Fairlie and Zachos, as well as the general ternary $q$-Virasoro-Witt algebras we construct, carry a structure of ternary Hom-Nambu-Lie algebra for all values of the involved parameters

Can the insider-outsider theory explain unemployment hysteresis in OECD countries?

Insider-outsider theory is often used as a basis for explaining the hysteretic behaviour of unemployment. Despite this, there is no empirical evidence about the validity of this theory on explaining the persistence of unemployment. This paper addresses this gap, using various labour market proxies of insiders' power for the OECD countries over 1960-2013 and employing panel unit root tests that exploit the information contained in these proxies. The results show that although the unemployment rate exhibits a pronounced hysteretic behaviour in OECD countries, this behaviour is reversed once we account for the insider-outsider proxies. Our findings thus validate the role of the insider-outsider theory as a key source of unemployment hysteresis

On Deformations of n-Lie algebras

The aim of this paper is to review the deformation theory of $n$-Lie algebras. We summarize the 1-parameter formal deformation theory and provide a generalized approach using any unital commutative associative algebra as a deformation base. Moreover, we discuss degenerations and quantization of $n$-Lie algebras.Comment: Proceeding of the conference Dakar's Workshop in honor of Pr Amin Kaidi. arXiv admin note: text overlap with arXiv:hep-th/9602016 by other author