On the Early Evolution of Forming Jovian Planets I: Initial Conditions, Systematics and Qualitative Comparisons to Theory

(abridged) We analyze the formation and migration of a proto-Jovian companion in a circumstellar disk in 2d, during the period in which the companion makes its transition from `Type I' to `Type II' migration, using a PPM code. Spiral waves are generated by the gravitational torque of the planet on the disk. Their effects are to cause the planet to migrate inward and the disk to form a deep (low surface density) gap. Until a transition to slower Type II migration, the migration rate of the planet is of order 1 AU/10$^3$ yr, and varies by less than a factor of two with a factor twenty change in planet mass, but depends near linearly on the disk mass. Although the disk is stable to self gravitating perturbations (Toomre $Q>5$ everywhere), migration is faster by a factor of two or more when self gravity is suppressed. Migration is equally sensitive to the disk's mass distribution within 1--2 Hill radii of the planet, as demonstrated by our simulations' sensitivity to the planet's assumed gravitational softening parameter. Rapid migration can continue after gap formation. Gaps are typically several AU in width and display the \mplan$^{2/3}$ proportionality predicted by theory. Beginning from an initially unperturbed 0.05\msun disk, planets of mass $M_{\rm pl}> 0.3$\mj can open a gap deep and wide enough to complete the transition to slower \ttwo migration. Lower mass objects continue to migrate rapidly, eventually impacting the inner boundary of our grid. This transition mass is much larger than that predicted as the `Shiva mass' discussed in Ward and Hahn (2000), making the survival of forming planets even more precarious than they would predict.Comment: 39 pages incl 13 figures. High resolution color figures at http://www.maths.ed.ac.uk/~andy/publications.htm

Entanglement and out-of-equilibrium dynamics in holographic models of de Sitter QFTs

In this paper we study various aspects of entanglement entropy in strongly-coupled de Sitter quantum field theories in various dimensions. We find gravity solutions that are dual to field theories in a fixed de Sitter background, both in equilibrium and out-of-equilibrium configurations. The latter corresponds to the Vaidya generalization of the AdS black hole solutions with hyperbolic topology. We compute analytically the entanglement entropy of spherical regions and show that there is a transition when the sphere is as big as the horizon. We also explore thermalization in time-dependent situations in which the system evolves from a non-equilibrium state to the Bunch-Davies state. We find that the saturation time is equal to the light-crossing time of the sphere. This behavior is faster than random walk and suggests the existence of free light-like degrees of freedom.Comment: 39 pages, 11 figures; minor changes, conclusions unchange

Fluctuation and dissipation in de Sitter space

In this paper we study some thermal properties of quantum field theories in de Sitter space by means of holographic techniques. We focus on the static patch of de Sitter and assume that the quantum fields are in the standard Bunch-Davies vacuum. More specifically, we follow the stochastic motion of a massive charged particle due to its interaction with Hawking radiation. The process is described in terms of the theory of Brownian motion in inhomogeneous media and its associated Langevin dynamics. At late times, we find that the particle undergoes a regime of slow diffusion and never reaches the horizon, in stark contrast to the usual random walk behavior at finite temperature. Nevertheless, the fluctuation-dissipation theorem is found to hold at all times.Comment: 1+45 pages, 5 figures. v4: matches published versio

ANALISIS FAKTOR-FAKTOR YANG MEMPENGARUHI KEUNTUNGAN USAHA FOTOCOPY DI SEKITAR KAMPUS UNS SURAKARTA

The purpose of this study was to analyze: 1) The effect of capital factor, 2) The influence of age, 3) Effect of educational success factor, 4) Influence factors of business experience to the business profits copy around campus UNS Surakarta and 5) the impact of capital factors, age, education, and business experience together to benefit businesses around campus photocopy UNS Surakarta. This study uses descriptive statistics, which explains the current situation using a statistical analysis tool. Research conducted around campus University of March by taking samples of the entire population of some 40 businessmen copy. Data obtained by questionnaire. Analysis using multiple regression analysis. Based on the results of data analysis has been performed, we can conclude some of the following: 1) There is significant relationship between venture capital business profits simultaneously to copy around the campus of the University of March Surakarta. 2) There is a significant relationship between the experience of business to business profits around the University campus photocopy of March Surakarta. 3) There is no significant influence of age on the benefit of business around the University campus photocopy of March Surakarta. 4) There is a significant relationship between the educational success of business profits around the University campus photocopy of March Surakarta. 5) There is a significant relationship between venture capital, business experience, age, and education successfully together to benefit businesses around the University campus photocopy of March Surakarta. Keywords: Business photocopy, Profit, Capital Business, Success Education, age, business experience

The right to live and the right to die?

With the advance of medical science and technology, dying can be postponed now. For how long and how is the quality of life? Frequently modern medicine postpones death only, while leaving the quality of life of many patients in a questionable state. Do we have the right to live? Where do we get that right from? The right to live is inherent to our nature of being alive. With right comes obligation. What about the right to die? Some say if there is the right to live, there must also be the right to die. What is life and what is death anyway? Some say death is part of life. Death is in fact the absence of life. We can measure life, but we can not measure death. It’s like stating that darkness is part of light. Also, if there is the right to die, what obligations on earth does a dead person have? ‘The right to live’ excludes ‘the right to die’. This moral philosophical approach is only following our moral-ethical reasoning (not our emotions). If we have ‘the right to die’, it is not far from having ‘the right to kill’ or may be ‘the duty to die’. The battle between the pros and the cons on the right to die is not over yet. We may consider the transcendental approach. When curative medicine is of no benefit anymore, care giving and ministering medicine must take its place. The transcendental approach takes the dying person as a bio-psycho-socio-cultural-spiritual being with the belief in life after death, and the ‘exit’ is with faith, hope and love. It is much more optimistic and relieving than the worldly approaches with an ‘exit’ because of despair