An optimal gap theorem

By solving the Cauchy problem for the Hodge-Laplace heat equation for $d$-closed, positive $(1, 1)$-forms, we prove an optimal gap theorem for K\"ahler manifolds with nonnegative bisectional curvature which asserts that the manifold is flat if the average of the scalar curvature over balls of radius $r$ centered at any fixed point $o$ is a function of $o(r^{-2})$. Furthermore via a relative monotonicity estimate we obtain a stronger statement, namely a `positive mass' type result, asserting that if $(M, g)$ is not flat, then $\liminf_{r\to \infty} \frac{r^2}{V_o(r)}\int_{B_o(r)}\mathcal{S}(y)\, d\mu(y)>0$ for any $o\in M$

The effect of the motion of the Sun on the light-time in interplanetary relativistic experiments

In 2002 a measurement of the effect of solar gravity upon the phase of coherent microwave beams passing near the Sun has been carried out with the Cassini mission, allowing a very accurate measurement of the PPN parameter $\gamma$. The data have been analyzed with NASA's Orbit Determination Program (ODP) in the Barycentric Celestial Reference System, in which the Sun moves around the centre of mass of the solar system with a velocity $v_\odot$ of about 10 m/sec; the question arises, what correction this implies for the predicted phase shift. After a review of the way the ODP works, we set the problem in the framework of Lorentz (and Galilean) transformations and evaluate the correction; it is several orders of magnitude below our experimental accuracy. We also discuss a recent paper \cite{kopeikin07}, which claims wrong and much larger corrections, and clarify the reasons for the discrepancy.Comment: Final version accepted by Classical and Quantum Gravity (8 Jan. 2008

Non-minimal coupling of photons and axions

We establish a new self-consistent system of equations accounting for a non-minimal interaction of gravitational, electromagnetic and axion fields. The procedure is based on a non-minimal extension of the standard Einstein-Maxwell-axion action. The general properties of a ten-parameter family of non-minimal linear models are discussed. We apply this theory to the models with pp-wave symmetry and consider propagation of electromagnetic waves non-minimally coupled to the gravitational and axion fields. We focus on exact solutions of electrodynamic equations, which describe quasi-minimal and non-minimal optical activity induced by the axion field. We also discuss empirical constraints on coupling parameters from astrophysical birefringence and polarization rotation observations.Comment: 31 pages, 2 Tables; replaced with the final version published in Classical and Quantum Gravit

Non-ancient solution of the Ricci flow

For any complete noncompact K$\ddot{a}$hler manifold with nonnegative and bounded holomorphic bisectional curvature,we provide the necessary and sufficient condition for non-ancient solution to the Ricci flow in this paper.Comment: seven pages, latex fil

Pengaruh Leverage dan Likuiditas terhadap Kebijakan Dividen dengan Profitabilitas sebagai Variabel Intervening di Bei

Kebijakan dividen merupakan keputusan keuangan yang dilakukan oleh Perusahaan setelah Perusahaan beroperasi dan memperoleh laba. Penelitian ini bertujuan untuk mengetahui pengaruh leverage dan likuiditas terhadap kebijakan dividen dengan profitabilitas sebagai variable moderasi di BEI. Metode yang digunakan untuk menentukan sampel adalah non-probability yaitu purposive sampling dengan ukuran sampel sebanyak 51 Perusahaan manufaktur yang di BEI sesuai kriteria tertentu. Pengumpulan data dilakukan dengan metode observasi non partisipan. Teknik analisis data yang digunakan adalah analisis jalur atau path analysis diserta dengan uji sobel. Hasil penelitian menunjukkan bahwa leverage berpengaruh signifikan terhadap profitabilitas dan kebijakan dividen. Likuiditas berpengaruh signifikan terhadap profitabilitas, namun tidak signifikan terhadap kebijakan dividen. Leverage secara tidak berpengaruh signifikan terhadap kebijakan dividen melalui profitabilitas, sedangkan likuiditas secara berpengaruh signifikan terhadap kebijakan dividen melalui profitabilitas. Implikasi praktis yang diperoleh dari penelitian ini bahwa hendakya ketiga variabel tersebut memperoleh perhatian lebih besar dari manajemen keuangan Perusahaan manufaktur dalam menentukan kebijakan dividen.   Kata kunci: leverage, likuiditas, profitabilitas, kebijakan dividen &nbsp

Meningkatkan Aktivitas Dan Prestasi Belajar Siswa Melalui Penerapan Model Pembelajaran Qt Dengan Kerangka Tandur Dalam Pembelajaran Bangun Segi Empat Pada Siswa Kelas VII C SMP Pancasila Canggu Tahun Pelajaran 2011/2012

Mathematics should be taught interestingly. One of the interesting learning models is Quantum Teaching (QT). In this study, QT model is applied in the class VII C SMP Pancasila Canggu, in the academic year 2011/2013. The goals were to improve the activities and achievements of student learning through the application of models by QT TANDUR method and to find out how the response of against the application of QT framework with model TANDUR in learning up a rectangle. The results shown that an average score of learning activities in cycle I, II, III for consecutive 9,66, 12.32, and 14,18. It is categorized as active enough, active, and active. Further, there was improvement seen from the results of student learning achievement based on the average class (X ), absorbance (DS), and the mastery learning (KB); cycle I are: 64,15 64,15,%, 60,97%, cycle II: 77,33 77,33% 88,37,%, and in cycle III: 80.00 80.00%, 93,02%