Aging dynamics in quenched noisy long-range quantum Ising models

We consider the $d$-dimensional transverse-field Ising model with power-law interactions $J/r^{d+\sigma}$ in the presence of a noisy longitudinal field with zero average. We study the longitudinal-magnetization dynamics of an initial paramagnetic state after a sudden switch-on of both the interactions and the noisy field. While the system eventually relaxes to an infinite-temperature state with vanishing magnetization correlations, we find that two-time correlation functions show aging at intermediate times. Moreover, for times shorter than the inverse noise strength $\kappa$ and distances longer than $a(J/\kappa)^{2/\sigma}$ with $a$ being the lattice spacing, we find a critical scaling regime of correlation and response functions consistent with the model A dynamical universality class with an initial-slip exponent $\theta=1$ and dynamical critical exponent $z=\sigma/2$. We obtain our results analytically by deriving an effective action for the magnetization field including the noise in a non-perturbative way. The above scaling regime is governed by a non-equilibrium fixed point dominated by the noise fluctuations.Comment: Accepted version, 11 pages, 5 figure

Scalar-tensor theories, trace anomalies and the QCD-frame

We consider the quantum effects of matter fields in scalar-tensor theories and clarify the role of trace anomaly when switching between conformally related `frames'. We exploit the property that the couplings between the scalar and the gauge fields are not frame-invariant in order to define a `QCD-frame', where the scalar is not coupled to the gluons. We show that this frame is a natural generalization of the `Jordan frame' in the case of non-metric theories and that it is particularly convenient for gravitational phenomenology: test bodies have trajectories that are as close as possible to geodesics with respect to such a metric and equivalence principle violations are directly proportional to the scalar coupling parameters written in this frame. We show how RG flow and decoupling work in metric and non-metric theories. RG-running commutes with the operation of switching between frames at different scales. When only matter loops are considered, our analysis confirms that metricity is stable under radiative corrections and shows that approximate metricity is natural in a technical sense.Comment: 10 pages. Minor changes to the main text, appendix added. To appear on PR

An integrated approach project for the revaluation of a traditional sourdough bread production chain

The influence of organic and conventional farming systems on the performance of a panel of old and modern Italian bread wheat varieties has been evaluated, with the aim to individuate an agronomic protocol suitable for the production of a sourdough bread traditionally prepared in a hill zone of Emilia-Romagna. The agronomic and technological characterisation of the wheat samples obtained in organic and conventional farming conditions has been done and the sensorial qualities of the sourdough bread obtained have been evaluated

Catching the Gazelle: Antecedents and Outcomes of High Growth Firms

This three-essay dissertation seeks to resolve some of the unanswered questions that exist about high-growth firms (HGFs). Paper I identifies the antecedents and outcomes of HGFs to better inform economic development policy. In explaining the theoretical and operational constructs of these concepts, a model of the situation of high-growth firms is developed, dubbed the Model of High Growth Firm Antecedents and Outputs. Antecedents to HGFs include an entrepreneurial mindset, firm strategic resources, and firm structural characteristics, while outputs of HGFs include regional innovation outcomes and regional economic outcomes. Paper II investigated the quantitative association between antecedents and outputs of HGFs. This paper used path analysis to test hypotheses within the Regional High-Growth Firm Antecedents and Outcomes Framework, and finds a strong positive association between most antecedents (human capital, startup capital, and business costs) and HGFs, a positive relationship between most antecedents and outcomes (employment and per capita income), and an association between HGFs and employment. Paper III establishes a typology of HGFs using cluster-discriminate analysis. Using a sample of 26,104 firms in the state of Ohio from the Quarterly Census of Employment and Wages, this paper finds that only a small portion of HGFs display high-growth characteristics described in the literature

Catching the Gazelle: Antecedents and Outcomes of High Growth Firms

This three-essay dissertation seeks to resolve some of the unanswered questions that exist about high-growth firms (HGFs). Paper I identifies the antecedents and outcomes of HGFs to better inform economic development policy. In explaining the theoretical and operational constructs of these concepts, a model of the situation of high-growth firms is developed, dubbed the Model of High Growth Firm Antecedents and Outputs. Antecedents to HGFs include an entrepreneurial mindset, firm strategic resources, and firm structural characteristics, while outputs of HGFs include regional innovation outcomes and regional economic outcomes. Paper II investigated the quantitative association between antecedents and outputs of HGFs. This paper used path analysis to test hypotheses within the Regional High-Growth Firm Antecedents and Outcomes Framework, and finds a strong positive association between most antecedents (human capital, startup capital, and business costs) and HGFs, a positive relationship between most antecedents and outcomes (employment and per capita income), and an association between HGFs and employment. Paper III establishes a typology of HGFs using cluster-discriminate analysis. Using a sample of 26,104 firms in the state of Ohio from the Quarterly Census of Employment and Wages, this paper finds that only a small portion of HGFs display high-growth characteristics described in the literature

Catching the Gazelle: Antecedents and Outcomes of High Growth Firms

This three-essay dissertation seeks to resolve some of the unanswered questions that exist about high-growth firms (HGFs). Paper I identifies the antecedents and outcomes of HGFs to better inform economic development policy. In explaining the theoretical and operational constructs of these concepts, a model of the situation of high-growth firms is developed, dubbed the Model of High Growth Firm Antecedents and Outputs. Antecedents to HGFs include an entrepreneurial mindset, firm strategic resources, and firm structural characteristics, while outputs of HGFs include regional innovation outcomes and regional economic outcomes. Paper II investigated the quantitative association between antecedents and outputs of HGFs. This paper used path analysis to test hypotheses within the Regional High-Growth Firm Antecedents and Outcomes Framework, and finds a strong positive association between most antecedents (human capital, startup capital, and business costs) and HGFs, a positive relationship between most antecedents and outcomes (employment and per capita income), and an association between HGFs and employment. Paper III establishes a typology of HGFs using cluster-discriminate analysis. Using a sample of 26,104 firms in the state of Ohio from the Quarterly Census of Employment and Wages, this paper finds that only a small portion of HGFs display high-growth characteristics described in the literature

Catching the Gazelle: Antecedents and Outcomes of High Growth Firms

This three-essay dissertation seeks to resolve some of the unanswered questions that exist about high-growth firms (HGFs). Paper I identifies the antecedents and outcomes of HGFs to better inform economic development policy. In explaining the theoretical and operational constructs of these concepts, a model of the situation of high-growth firms is developed, dubbed the Model of High Growth Firm Antecedents and Outputs. Antecedents to HGFs include an entrepreneurial mindset, firm strategic resources, and firm structural characteristics, while outputs of HGFs include regional innovation outcomes and regional economic outcomes. Paper II investigated the quantitative association between antecedents and outputs of HGFs. This paper used path analysis to test hypotheses within the Regional High-Growth Firm Antecedents and Outcomes Framework, and finds a strong positive association between most antecedents (human capital, startup capital, and business costs) and HGFs, a positive relationship between most antecedents and outcomes (employment and per capita income), and an association between HGFs and employment. Paper III establishes a typology of HGFs using cluster-discriminate analysis. Using a sample of 26,104 firms in the state of Ohio from the Quarterly Census of Employment and Wages, this paper finds that only a small portion of HGFs display high-growth characteristics described in the literature