We investigate the spectral types of families of discrete one-dimensional Schrödinger operators { H ω } ω ∈ Ω , where each H _ω has a potential function V _ω (n) = f(T ⁿ ω) for n ∈ Z , T is an ergodic homeomorphism on a compact space Ω and f : Ω → R is a continuous function. The main analytical tool of the paper is Gordon’s lemma, of which we provide a complete proof. We demonstrate that a generic operator H ω ∈ { H ω } ω ∈ Ω has purely continuous spectrum if { T n α } n ≥ 0 is dense in Ω for a certain α ∈ Ω. Furthermore, we extend this result to the case where {Ω, T} satisfies topological repetition property, a concept introduced by Boshernitzan and Damanik (2008, [1]). Theorems presented in this paper weaken the hypotheses of previous research and enable us to reach the same conclusion as those authors. Our paper presents a comprehensive study of the topological and metric repetition properties, highlighting their binding role between the theory of dynamical systems and spectral theory. We also discuss the implications of these properties on the qualitative description of specific physical systems.

La cuantificación monetaria de las externalidades ambientales derivadas de la explotación de hidrocarburos no convencionales que utiliza la técnica de fracturación hidráulica o fracking muestra una alta variabilidad pues sus costos no están unívocamente determinados. En este documento desarrollamos un análisis de metarregresión sobre los posibles efectos económicos atribuibles a la proximidad de entornos que puedan verse afectados ambientalmente por el fracking. Las categorías de impacto analizadas son: 1) contaminación de fuentes de agua, 2) disposición de residuos peligrosos, 3) contaminación del aire y 4) sismicidad inducida. Los resultados de nuestras estimaciones sugieren un efecto de mayor magnitud y significancia para las dos primeras. Se muestra también que aspectos metodológicos y externos a las investigaciones tales como el año de la publicación del estudio o la especificación utilizada influyen sobre la estimación de los costos.

This study investigates the intricate relationship between Venezuelan migration and urban growth in Colombia from 2018 to 2021. The study employs remote sensing data and social network metrics to uncover migration patterns and their impact on urban expansion. The methodology consists of three stages. Firstly, nighttime satellite imagery is used to analyze year-over-year urban growth in Colombia. Secondly, social network data estimates Venezuelan migration, overcoming challenges of underreporting and informal border crossings. Lastly, an econometric analysis explores the quantitative link between Venezuelan migration and urban growth, integrating socioeconomic variables to address endogeneity. The findings reveal the complex interplay of Venezuelan migration, socioeconomic factors, and urban growth. The study outlines remote sensing analysis, introducing the Anthropogenic Footprint Expansion Index (AFEI) to quantify urban growth. Facebook API data estimates migration trends and explores socioeconomic impacts on urban expansion. The analysis uncovers migration, poverty, aging, and urban population proportion as key factors affecting Colombia’s urban landscape. Furthermore, the research underscores how Venezuelan migration affected short-term urban expansion pre- and post-COVID-19. Migration had a notable effect before the pandemic, but this influence waned afterward. The study highlights migration’s short-term nature and emphasizes age demographics’ role in medium-term dynamics.

This study investigates the intricate relationship between Venezuelan migration and urban growth in Colombia from 2018 to 2021. The study employs remote sensing data and social network metrics to uncover migration patterns and their impact on urban expansion. The methodology consists of three stages. Firstly, nighttime satellite imagery is used to analyze year-over-year urban growth in Colombia. Secondly, social network data estimates Venezuelan migration, overcoming challenges of underreporting and informal border crossings. Lastly, an econometric analysis explores the quantitative link between Venezuelan migration and urban growth, integrating socioeconomic variables to address endogeneity. The findings reveal the complex interplay of Venezuelan migration, socioeconomic factors, and urban growth. The study outlines remote sensing analysis, introducing the Anthropogenic Footprint Expansion Index (AFEI) to quantify urban growth. Facebook API data estimates migration trends and explores socioeconomic impacts on urban expansion. The analysis uncovers migration, poverty, aging, and urban population proportion as key factors affecting Colombia's urban landscape. Furthermore, the research underscores how Venezuelan migration affected short-term urban expansion pre- and post-COVID-19. Migration had a notable effect before the pandemic, but this influence waned afterward. The study highlights migration's short-term nature and emphasizes age demographics' role in medium-term dynamics.

We study the spectral types of the families of discrete one-dimensional Schrödinger operators $\{H_ω\}_{ω\inΩ}$, where the potential of each $H_ω$ is given by $V_ω(n)=f(T^nω)$ for $n\in\mathbb{Z}$, $T$ is an ergodic homeomorphism on a compact space $Ω$ and $f:Ω\rightarrow\mathbb{R}$ is a continuous function. We show that a generic operator $H_ω\in \{H_ω\}_{ω\inΩ}$ has purely continuous spectrum if $\{T^nα\}_{n\geq0}$ is dense in $Ω$ for a certain $α\inΩ$. We also show the former result assuming only that $\{Ω, T\}$ satisfies topological repetition property ($TRP$), a concept introduced by Boshernitzan and Damanik (arXiv:0708.1263v1). Theorems presented in this paper weaken the hypotheses of the cited research and allow us to reach the same conclusion as those authors. We also provide a proof of Gordon's lemma, which is the main tool used in this work.

Crowdfunding has emerged as an alternative financing mechanism that reduces entry barriers for diverse groups. However, whether the gender composition of entrepreneurs’ leadership teams affects campaign success remains an open question. This study examines how two key determinants of crowdfunding success, quality signaling strategies and team size, vary with the gender composition of management teams. We apply structural equation modeling, a particularly suitable yet seldom employed method in crowdfunding research, in order to test both the direct effect and the indirect effect of gender on success level channeled through management team strategies. Using data from Crowdcube, a leading crowdfunding investment platform, we find that these indirect effect implies up to 33.4% lower success level of female-led teams compared to their male-led counterparts. Interestingly, we also find that the size of the team does not have a direct effect on success; its influence operates through the signaling strategy adopted. These findings underscore the central role of management strategies in shaping campaign outcomes and suggest that gender disparities in success stem from differential strategic signaling behavior. JEL Classification: G14 , D26 , M13 , J16 , C30