Conformal Gravity from AdS/CFT mechanism

We explicitly calculate the induced gravity theory at the boundary of an asymptotically Anti-de Sitter five dimensional Einstein gravity. We also display the action that encodes the dynamics of radial diffeomorphisms. It is found that the induced theory is a four dimensional conformal gravity plus a scalar field. This calculation confirms some previous results found by a different approach.Comment: Revtex 8 pages, To be published in Phys. Rev.

International Lessons for Promoting Transit Connections to High-Speed Rail Systems

As the California High-Speed Rail (HSR) project becomes reality, many communities involved in, or affected by, the California HSR project have considered how to connect the new HSR passenger services to local urban transportation systems – such as bus and light rail systems – and how they can take advantage of HSR accessibility and speed throughout the state. European and other overseas systems have decades of experience in forging connections between HSR and various transportation options. This study examines international HSR stations and identifies patterns in transit connections associated with stations on the basis of size, population levels, and other characteristics. Additionally, a closer examination is made of the lessons that can be learned from a strategic sample of overseas HSR stations, correlated to similar cities in the planned California system. Generally, the findings from the comparison suggest that California cities must make significant strides to approach the level of integration and ease of access to other modes that systems outside the U.S. now enjoy

Transient tunneling effects of resonance doublets in triple barrier systems

Transient tunneling effects in triple barrier systems are investigated by considering a time-dependent solution to the Schr\"{o}dinger equation with a cutoff wave initial condition. We derive a two-level formula for incidence energies $E$ near the first resonance doublet of the system. Based on that expression we find that the probability density along the internal region of the potential, is governed by three oscillation frequencies: one of them refers to the well known Bohr frequency, given in terms of the first and second resonance energies of the doublet, and the two others, represent a coupling with the incidence energy $E$. This allows to manipulate the above frequencies to control the tunneling transient behavior of the probability density in the short-time regim

Stereodivergent, Diels-Alder-initiated organocascades employing α,β-unsaturated acylammonium salts: scope, mechanism, and application.

Chiral α,β-unsaturated acylammonium salts are novel dienophiles enabling enantioselective Diels-Alder-lactonization (DAL) organocascades leading to cis- and trans-fused, bicyclic γ- and δ-lactones from readily prepared dienes, commodity acid chlorides, and a chiral isothiourea organocatalyst under mild conditions. We describe extensions of stereodivergent DAL organocascades to other racemic dienes bearing pendant secondary and tertiary alcohols, and application to a formal synthesis of (+)-dihydrocompactin is described. A combined experimental and computational investigation of unsaturated acylammonium salt formation and the entire DAL organocascade pathway provide a rationalization of the effect of Brønsted base additives and enabled a controllable, diastereodivergent DAL process leading to a full complement of possible stereoisomeric products. Evaluation of free energy and enthalpy barriers in conjunction with experimentally observed temperature effects revealed that the DAL is a rare case of an entropy-controlled diastereoselective process. NMR analysis of diene alcohol-Brønsted base interactions and computational studies provide a plausible explanation of observed stabilization of exo transition-state structures through hydrogen-bonding effects

Voices Against Discrimination and Exclusion: Latino School Leaders\u27 Narratives for Change

Many scholars, practitioners, and policy makers know very little about individual Latino administrators\u27 cultural and professional experiences, responses to discrimination, and patterns or institutional conditions which relate to K-12 ethnic minority administrators\u27 success. Moreover, many are also unaware that as ethnic diversity increases, the relative proportion of minority administrators, many of whom could be role models, shrinks. Once we can recognize this as seeds for inequity in society, we might be able to consider the ways in which our educational institution reinforces or counters societal inequities. By specifically exploring Latino administrators\u27 experiences, because of the large Latino California presence, we may gain insight into the larger societal or organizational context. That data may, in turn, help scholars, practitioners and policy makers become more equitable and democratic. This study is important because, in a heightened way, educators and other public officials are charged with drawing forth and making real what we represent: the democratic ideal. Through a qualitative multiple-case study approach, I carried out a series of in-depth interviews for exploring Latino administrators\u27 experiences and understandings related to white privilege, inequities and the challenges to democracy in K-12 education. The data suggests that the participants work in educational settings which are often characterized by blunt and persistent exclusion. Nonetheless, in spite of many obstacles, participants appear to have achieved both cultural integrity and professional advancement without remaining limited by the isolation created by white privilege. In many cases, subjects are educational or professional pioneers, carving their own paths and building their own support networks for other Latinos\u27 benefit

Rare top decay and CP violation in THDM

We discuss the formalism of two Higgs doublet model type III with CP violation from CP-even CP-odd mixing in the neutral Higgs bosons. The flavor changing interactions among neutral Higgs bosons and fermions are presented at tree level in this type of model. These assumptions allow the study rare top decays mediated by neutral Higgs bosons, particularly we are interested in $t\rightarrow c l^+l^-$. For this process we estimated upper bounds of the branching ratios $\textrm{Br}(t\rightarrow c \tau^+\tau^-)$ of the order of $10^{-9}\sim 10^{-7}$ for a neutral Higgs boson mass of 125 GeV and $\tan\beta=1$, 1.5, 2, 2.5. For the case of $t\rightarrow c \tau^+\tau^-$ the number of possible events is estimated from 1 to 10 events which could be observed in future experiments at LHC with a luminosity of 300 $\textrm{fb}^{-1}$ and 14 GeV for the energy of the center of mass. Also we estimate that the number of events for the process $t\rightarrow c l^+l^-$ in different scenarios is of order of $2500$.Comment: 8 pages, 5 figure