Notes on optimality conditions using Newton diagrams and sums of squares

We consider relationships between optimality conditions using Newton diagrams and sums of squares of polynomials and power series.Comment: Corrected version of the article [Serdica Math. J.(2015) 41, pp. 431-456

"A Characterization of the Plurality Rule"

We consider an axiomatic characterization of the plurality rule, which selects the alternative(s) most preferred by the largest number of individuals. We strengthen the characterization result of Yeh (Economic Theory 34: 575{583, 2008) by replacing effciency axiom by the weaker axiom called faithfulness . Formally, we show that the plurality rule is the only rule satisfying anonymity, neutrality, reinforcement, tops-only , and faithfulness .

Career Development of College Students through Part-Time Work: The Role of Leader-Member Exchange and Taking Charge Behavior

This study examines the potential benefit of college students' part-time work on their career development by focusing on leader-member exchange (LMX) and taking charge behavior in the workplace. Using a sample of Japanese college students, results from this study indicate that taking charge behavior in part-time work mediates the relationship between LMX quality with supervisors and career development (focus of career exploration, self-efficacy toward postcollege employment and proactive career behavior). The results also indicate that proactive personality and conscientiousness moderate the relationship between LMX quality and taking charge behavior, and that job autonomy and skill variety moderate the relationship between taking charge behaviors and career development. Implications for theory and practice are discussed.part-time work, leader-member exchange, taking charge behavior, career development, college student

Low-Energy Dynamics of 3d N=2\mathcal{N}=2 G2G_2 Supersymmetric Gauge Theory

We study a three-dimensional $\mathcal{N}=2$ supersymmetric $G_2$ gauge theory with and without fundamental matters. We find that a classical Coulomb branch of the moduli space of vacua is partly lifted by monopole-instantons and the quantum Coulomb moduli space would be described by a complex one-dimensional space. Depending on the number of the matters in a fundamental representation, the low-energy dynamics of the theory shows various phases like s-confinement or quantum merging of the Coulomb and the Higgs branches. We also investigate superconformal indices as an independent check of our analysis.Comment: v2 typo correcte

Cosmological Constraints on Isocurvature and Tensor Perturbations

We investigate cosmological constraints on primordial isocurvature and tensor perturbations, using recent observations of the cosmic microwave background and the large scale structure. We find that present observations are consistent with purely adiabatic initial conditions for the structure formation under any priors on correlations of isocurvature modes, and upper limits on the contribution of isocurvature and tensor perturbations are presented. We also apply the obtained constraints to some specific theoretical models, axion isocurvature perturbation models and curvaton models, and give some implications for theoretical models.Comment: 24 pages, 8 figure

Automorphisms of hyperelliptic modular curves X0(N)X_0(N) in positive characteristic

We study the automorphism groups of the reduction $X_0(N) \times \bar{\mathbb{F}}_p$ of a modular curve $X_0(N)$ over primes $p\nmid N$