On the Initial Conditions for Brane Inflation

String theory gives rise to various mechanisms to generate primordial inflation, of which ``brane inflation'' is one of the most widely considered. In this scenario, inflation takes place while two branes are approaching each other, and the modulus field representing the separation between the branes plays the role of the inflaton field. We study the phase space of initial conditions which can lead to a sufficiently long period of cosmological inflation, and find that taking into account the possibility of nonvanishing initial momentum can significantly change the degree of fine tuning of the required initial conditions.Comment: 11 pages, 2 figure

Energy Conditions in f(G)f(G) Modified Gravity with Non-minimal Coupling to Matter

In this paper we study a model of modified gravity with non-minimal coupling between a general function of the Gauss-Bonnet invariant, $f(G)$, and matter Lagrangian from the point of view of the energy conditions. Such model has been introduced in Ref. [21] for description of early inflation and late-time cosmic acceleration. We present the suitable energy conditions for the above mentioned model and then, we use the estimated values of the Hubble, deceleration and jerk parameters to apply the obtained energy conditions to the specific class of modified Gauss-Bonnet models.Comment: 12 pages, no figur, Accepted for publication in Astrophysics and Space Scienc

Modified f(G) gravity models with curvature-matter coupling

A modified f(G) gravity model with coupling between matter and geometry is proposed, which is described by the product of the Lagrange density of the matter and an arbitrary function of the Gauss-Bonnet term. The field equations and the equations of motion corresponding to this model show the non-conservation of the energy-momentum tensor, the presence of an extra-force acting on test particles and the non-geodesic motion. Moreover, the energy conditions and the stability criterion at de Sitter point in the modified f(G) gravity models with curvature-matter coupling are derived, which can degenerate to the well-known energy conditions in general relativity. Furthermore, in order to get some insight on the meaning of these energy conditions, we apply them to the specific models of f(G) gravity and the corresponding constraints on the models are given. In addition, the conditions and the candidate for late-time cosmic accelerated expansion in the modified f(G) gravity are studied by means of conditions of power-law expansion and the equation of state of matter less than -1/ 3 .Comment: 13 pages, 4 figure

Peranan Modal Dari Keluarga Pada 3 UKM di Bandung

Usaha kecil dan menengah menjadi bagian terbesar dari dunia usaha di Indonesia ,  yang telah  terbukti mampu bertahan selama masa krisis, tahun 1997-1998 dan tahun 2008. Usaha skala kecil dan menengah ini (UKM) memiliki peran penting terhadap perkembangan ekonomi, menyerap jumlah tenaga kerja yang banyak memberikan kontribusi terhadap GDP. Ada suatu fakta yang belum cukup  dipahami , bahwa berdirinya usaha skala kecil dan menengah umumnya dimulai dengan melibatkan anggota keluarga atau tidak langsung  mendapat dukungan dan bantuan keluarga . Penelitian ini difokuskan untuk menemukan   peran  modal  yang diberikan oleh keluarga pada saat pendirian usaha dan dalam perkembangannya,  baik modal yang  berupa uang dan finansial (harta tetap atau harta lancar), maupun yang bersifat nilai-nilai (family capital), dan emosi-waktu-perhatian (psychological capital) , dsb . Penelitian dilaksanakan dengan metode kualitatif yakni Multi Case Studies. Tiga UKM  di Bandung  dipilih sebagai obyek penelitian.  Teknik wawancara dan observasi digunakan saling melengkapi   . Hasil transkrip wawancara dikategorisasi (coding) sesuai tema penelitian. Teori modal Bourdieu (1996) digunakan untuk menganalisis dan untuk mendapatkan pemaknaan dari temuan. Temuan menunjukkan bahwa modal ekonomi bukanlah satu-satunya faktor yang berperan dalam memulai dan mengembangkan usaha dalam 3 kasus ini.  Ada  modal yang lain yaitu modal budaya dan modal sosial yang punya peran penting  terhadap awal dan  kelangsungan usaha. Modal simbolik dapat  dibangun dari   modal budaya  sejalan dengan berjalannya usaha dalam  jangka waktu yang cukup   lama. Kata-kata Kunci : modal ekonomi, modal budaya, modal sosial, modal simboli

From the Big Bang Theory to the Theory of a Stationary Universe

We consider chaotic inflation in the theories with the effective potentials phi^n and e^{\alpha\phi}. In such theories inflationary domains containing sufficiently large and homogeneous scalar field \phi permanently produce new inflationary domains of a similar type. We show that under certain conditions this process of the self-reproduction of the Universe can be described by a stationary distribution of probability, which means that the fraction of the physical volume of the Universe in a state with given properties (with given values of fields, with a given density of matter, etc.) does not depend on time, both at the stage of inflation and after it. This represents a strong deviation of inflationary cosmology from the standard Big Bang paradigm. We compare our approach with other approaches to quantum cosmology, and illustrate some of the general conclusions mentioned above with the results of a computer simulation of stochastic processes in the inflationary Universe.Comment: No changes to the file, but original figures are included. They substantially help to understand this paper, as well as eternal inflation in general, and what is now called the "multiverse" and the "string theory landscape." High quality figures can be found at http://www.stanford.edu/~alinde/LLMbigfigs

Therapeutic targeting of ATR in alveolar rhabdomyosarcoma

Despite advances in multi-modal treatment approaches, clinical outcomes of patients suffering from PAX3-FOXO1 fusion oncogene-expressing alveolar rhabdomyosarcoma (ARMS) remain dismal. Here we show that PAX3-FOXO1-expressing ARMS cells are sensitive to pharmacological ataxia telangiectasia and Rad3 related protein (ATR) inhibition. Expression of PAX3-FOXO1 in muscle progenitor cells is not only sufficient to increase sensitivity to ATR inhibition, but PAX3-FOXO1-expressing rhabdomyosarcoma cells also exhibit increased sensitivity to structurally diverse inhibitors of ATR. Mechanistically, ATR inhibition leads to replication stress exacerbation, decreased BRCA1 phosphorylation and reduced homologous recombination-mediated DNA repair pathway activity. Consequently, ATR inhibitor treatment increases sensitivity of ARMS cells to PARP1 inhibition in vitro, and combined treatment with ATR and PARP1 inhibitors induces complete regression of primary patient-derived ARMS xenografts in vivo. Lastly, a genome-wide CRISPR activation screen (CRISPRa) in combination with transcriptional analyses of ATR inhibitor resistant ARMS cells identifies the RAS-MAPK pathway and its targets, the FOS gene family, as inducers of resistance to ATR inhibition. Our findings provide a rationale for upcoming biomarker-driven clinical trials of ATR inhibitors in patients suffering from ARMS