Internal structure of a Maxwell-Gauss-Bonnet black hole

The influence of the Maxwell field on a static, asymptotically flat and spherically-symmetric Gauss-Bonnet black hole is considered. Numerical computations suggest that if the charge increases beyond a critical value, the inner determinant singularity is replaced by an inner singular horizon.Comment: 5 pages, 5 figures, published version with minor change

Observational Limits on Gauss-Bonnet and Randall-Sundrum Gravities

We discuss the possibilities of experimental search for new physics predicted by the Gauss-Bonnet and the Randall-Sundrum theories of gravity. The effective four-dimensional spherically-symmetrical solutions of these theories are analyzed. We consider these solutions in the weak-field limit and in the process of the primordial black holes evaporation. We show that the predictions of discussed models are the same as of General Relativity. So, current experiments are not applicable for such search therefore different methods of observation and higher accuracy are required.Comment: 7 pages, accepted to JET

Possible observation sequences of Brans-Dicke wormholes

The purpose of this study is to investigate observational features of Brans-Dicke wormholes in a case if they exist in our Universe. The energy flux from accretion onto a Brans-Dicke wormhole and the so-called "maximum impact parameter" are studied (the last one might allow to observe light sources through a wormhole throat). The computed values were compared with the corresponding ones for GR-wormholes and Schwarzschild black holes. We shown that Brans-Dicke wormholes are quasi-Schwarzschild objects and should differ from GR wormholes by about one order of magnitude in the accretion energy flux.Comment: 5 pages, 6 figure

Multi-model approach to quantify groundwater-level prediction uncertainty using an ensemble of global climate models and multiple abstraction scenarios

Acknowledgements. We acknowledge the World Climate Research Programme's Working Group on Coupled Modelling, which is responsible for CMIP, and we thank the climate modelling groups for producing and making available their model output. The fifth author obtained a PhD scholarship from the Fund for Scientific Research (FWO)-Flanders. This financial support is gratefully acknowledged. Data availability. The climate model data are publicly available through the website of the Earth System Grid Federation (https://esgf.llnl.gov, last access: 8 May 2019). Other data used in this study are summarized and presented in the figures, tables, references, and the Supplement. Additional data, model code and results are available upon request to the first ([email protected]) and last ([email protected]) authors.Peer reviewedPublisher PD

The Link between Innovation and Productivity in Estonia’s Service Sectors

The emerging literature on the characteristics of innovation processes in the service sector has paid relatively little attention to the links between innovation and productivity. In this paper we investigate how the innovation-productivity relationship differs across various subbranches of the service sector. For the analysis we use the CDM structural model consisting of equations for innovation expenditures, innovation output, productivity and exports. We use data from the community innovation surveys for Estonia. We show that innovation is associated with increased productivity in the service sector. The results indicate surprisingly that the effect of innovation on productivity is stronger in the less knowledge-intensive service sectors, despite the lower frequency of innovative activities and the results of earlier literature. Non-technological innovation only plays a positive role in some specifications, despite its expected importance especially among the service firms. An additional positive channel of the effects of innovation on productivity may function through increased exports.http://deepblue.lib.umich.edu/bitstream/2027.42/133027/1/wp1012.pd

Tests of f(R)-gravity in binary pulsars

We develop the parameterized post-Keplerian approach for class of analytic f(R)-gravity models. Using the double binary pulsar system PSR J0737-3039 data we obtain restrictions on the parameters of this class of f(R)-models and show that f(R)-gravity is not ruled out by the observations in strong field regime