Anisotropic fluid inside a relativistic star

An anisotropic fluid with variable energy density and negative pressure is proposed, both outside and inside stars. The gravitational field is constant everywhere in free space (if we neglect the local contributions) and its value is of the order of $g = 10^{-8} cm/s^{2}$, in accordance with MOND model. With $\rho,~ p \propto 1/r$, the acceleration is also constant inside stars but the value is different from one star to another and depends on their mass $M$ and radius $R$. In spite of the fact that the spacetime is of Rindler type and curved even far from a local mass, the active gravitational energy on the horizon is $-1/4g$, as for the flat Rindler space, excepting the negative sign.Comment: 9 pages, refs added, new chapter added, no figure

Comparative analysis of Finno-Sinic management: In-depth study of the dimensions of cross-cultural friction and synergy in management of Finnish firms in Hong Kong

This study focuses on how cross-cultural synergy and friction emerge in Finno-Sinic management communication, decision-making and organisation empowerment. The paper is based on a qualitative methodology and in-depth interviews with Finnish and Chinese subjects in Finnish companies in Hong Kong. According to the results, the Finnish communication was found out to be frank, open and informal, in contrast to the subtler, more reserved and more formal Sinic communication pattern. The Finnish decision-making was “improvising” and rapid, while the Sinic preference was for a slower and more formal approach. The Finnish ideal of organisation empowerment was based on low organisational hierarchy and downward delegation of authority, while the Sinic model relied on socio-political bargaining and higher power distance. – Chinese ; Communication ; Cross-Cultural ; Decision-Making ; Empowerment ; Finland ; Hong Kong ; ManagementTämä tutkimus tarkastelee suomalais-kiinalaisen johtamisen kitkaa ja synergiaa viestinnässä, päätöksenteossa ja vallanjaossa organisaatiossa. Se perustuu kvalitatiiviselle metodologialle ja sen aineistona on käytetty Hong Kongissa toimivissa suomalaisyrityksissä tehtyjä suomalaisen ja kiinalaisen henkilöstön yvähaastatteluja. Tutkimustuloksien mukaan suomalainen viestintä on suoraa, avointa ja epämuodollista verrattuna Hong Kongin kiinalaiseen epäsuorempaan, varautuneempaan ja muodollisempaan viestintätyyliin. Vastaavasti suomalainen päätöksentekotapa havaittiin ”improvisoivaksi” ja nopeaksi, kun hongkongilaiset suosivat rauhallisempaa ja muodollisempaa päätöksentekomallia. Suomalainen ihanne organisaation vallanjaosta perustuu matalalle hierarkialle ja päätösvallan delegoimiselle organisaatiossa alaspäin Hong Kongin kiinalaisen toimintatavan pohjautuessa sosiopoliittiselle neuvottelulle ja suuremmalle vallanerolle

Konjugaatti

Tiivistelmä. Tutkielmassa perehdytään konjugaattiin joka on eräänlainen operaatio abstraktissa algebrassa. Konjugaattia ja sen ominaisuuksia tutkitaan sekä yleisellä tasolla, että erinlaisissa ominaisuuksiltaan eroavissa ryhmissä. Tutkielmassa käydään läpi konjugaatin määritelmän lisäksi siihen liittyviä määritelmiä, kuten konjugaattiluokka, normaali aliryhmä, ryhmän keskus ja tekijäryhmä

Initial Conditions for Vector Inflation

Recently, a model of inflation using non-minimally coupled massive vector fields has been proposed. For a particular choice of non-minimal coupling parameter and for a flat FRW model, the model is reduced to the model of chaotic inflation with massive scalar field. We study the effect of non-zero curvature of the universe on the onset of vector inflation. We find that in a curved universe the dynamics of vector inflation can be different from chaotic inflation, and the fraction of the initial conditions leading to inflationary solutions is reduced compared with the chaotic inflation case.Comment: 12 pages, 5 figures, version to be published in JCA

Illumination diagnosis for retrieval of reflections from ambient-noise seismic data in the Siilinjärvi mining site, Finland

Reflection seismic methods are becoming popular in mineral exploration, because they allow high-resolution delineation of the exploration targets, even at great depths. Seismic interferometry can be used to retrieve reflections from passive seismic data, removing the need for active seismic sources and, therefore, reducing the cost and environmental impact of exploration. The retrieval of reflections can be challenging, since passive seismic records are typically dominated by surface waves. Therefore, illumination diagnosis, a method which allows the isolation of the portions of the passive data where body-wave signals are stronger, can be a valuable step that improves the quality of the reflections retrieved from seismic interferometry and reduces the overall computational cost of the processing stage. Here, we validate the performance of the method to effectively isolate the portions of the passive data dominated by body waves and apply it on an ambient-noise seismic dataset acquired in the Siilinjärvi mining site in Finland