A note on absolute summability factors

In this paper, by using an almost increasing and $\delta$-quasi-monotone sequence, a general theorem on $\phi-{\mid{C},\alpha\mid}_k$ summability factors, which generalizes a result of Bor \cite{3} on ${\phi-\mid{C},1\mid}_k$ summability factors, has been proved under weaker and more general conditions.Comment: 4 page

The Success of Climate Change Performance Index in the Development of Environmental Investments: E-7 Countries

 Climate change is considered to be one of the biggest problems acknowledged globally today. Therefore, the causes of climate change and solutions to this problem are frequently investigated. For this reason, the purpose of this study is to empirically examine whether the ‘Climate Change Performance Index’ (CCPI) is successful in increasing environmental investments for E-7 countries with the data for the period of 2008–2023. To achieve this aim, the Parks-Kmenta estimator was used as the econometric method in the study. The study findings provide strong evidence that increases in the climate change performance support environmental investments. High climate change performance directs governments and investors toward investing in this area; therefore, environmental investments tend to increase. The study also examined the effects of population growth, real GDP and inflation on environmental investments. Accordingly, it has been concluded that population growth and inflation negatively affect environmental investments, while GDP positively affects environmental investments

Fractional Calculus Operator Emerging from the 2D Biorthogonal Hermite Konhauser Polynomials

In the present paper, we introduce a method to construct two variable biorthogonal polynomial families with the help of one variable biorthogonal and orthogonal polynomial families. By using this new technique, we define 2D Hermite Konhauser polynomials and we investigate several properties of them such as biorthogonality property, operational formula and integral representation. We further inverstigate their images under the Laplace transformations, fractional integral and derivative operators. Corresponding to these polynomials, we define the new type bivariate Hermite Konhauser Mittag Leffler function and obtain the similar properties for them. In order to establish new fractional calculus, we add two new parameters and consider 2D Hermite Konhauser polynomials and bivariate Hermite Konhauser Mittag Leffler function. We introduce an integral operator containing the modified bivariate Hermite Konhauser Mittag Leffler function in the kernel. We show that it satisify the semigroup property and obtain its left inverse operator, which corresponds to its fractional derivative operator