The Utopian

The paper was concerned with the future of the social housing complex in Poplar, East London called Robin Hood Gardens designed, conceived and built in the late 60's by Alison and Peter Smithson. The project and publication centred on the possible future for the building through a series of articles and conceptual visions created by us as the authors

Two-dimensional conformal field theory and the butterfly effect

We study chaotic dynamics in two-dimensional conformal field theory through out-of-time order thermal correlators of the form $\langle W(t)VW(t)V\rangle$. We reproduce bulk calculations similar to those of [1], by studying the large $c$ Virasoro identity block. The contribution of this block to the above correlation function begins to decrease exponentially after a delay of $\sim t_* - \frac{\beta}{2\pi}\log \beta^2E_w E_v$, where $t_*$ is the scrambling time $\frac{\beta}{2\pi}\log c$, and $E_w,E_v$ are the energy scales of the $W,V$ operators.Comment: v1: 14 pages plus appendices, 2 figures. v2: references updated and minor changes to the text. v3: minor error corrected in Appendix B, but the conclusion is unchange

A national survey of in-service staff activities and projects in business education.

Thesis (M.Ed.)--Boston Universit

The goldstone and goldstino of supersymmetric inflation

We construct the minimal effective field theory (EFT) of supersymmetric inflation, whose field content is a real scalar, the goldstone for time-translation breaking, and a Weyl fermion, the goldstino for supersymmetry (SUSY) breaking. The inflating background can be viewed as a single SUSY-breaking sector, and the degrees of freedom can be efficiently parameterized using constrained superfields. Our EFT is comprised of a chiral superfield X_NL containing the goldstino and satisfying X_NL^2 = 0, and a real superfield B_NL containing both the goldstino and the goldstone, satisfying X_NL B_NL = B_NL^3 = 0. We match results from our EFT formalism to existing results for SUSY broken by a fluid background, showing that the goldstino propagates with subluminal velocities. The same effect can also be derived from the unitary gauge gravitino action after embedding our EFT in supergravity. If the gravitino mass is comparable to the Hubble scale during inflation, we identify a new parameter in the EFT related to a time-dependent phase of the gravitino mass parameter. We briefly comment on the leading contributions of goldstino loops to inflationary observables.Comment: 32 pages, 2 figures. v3: clarifications and references added. Matches JHEP version. v2: typos fixed, footnote and references adde

Hawking-Page transition in holographic massive gravity

We study the Hawking-Page transition in a holographic model of field theories with momentum dissipation. We find that the deconfinement temperature strictly decreases as momentum dissipation is increased. For sufficiently strong momentum dissipation, the critical temperature goes to zero, indicating a zero-temperature deconfinement transition in the dual field theory.Comment: 17 pages, 1 figure, uncomment \newcommand*{\ShowCalculations}{} in the tex file for additional details. Journal version (PRD). Presentation clarified, reference added, and line spacing and title update

Localized shocks

We study products of precursors of spatially local operators, $W_{x_{n}}(t_{n}) ... W_{x_1}(t_1)$, where $W_x(t) = e^{-iHt} W_x e^{iHt}$. Using chaotic spin-chain numerics and gauge/gravity duality, we show that a single precursor fills a spatial region that grows linearly in $t$. In a lattice system, products of such operators can be represented using tensor networks. In gauge/gravity duality, they are related to Einstein-Rosen bridges supported by localized shock waves. We find a geometrical correspondence between these two descriptions, generalizing earlier work in the spatially homogeneous case.Comment: 23 pages plus appendices, 12 figures. v2: minor error in Appendix B corrected. v3: figure added to the introduction comparing the butterfly effect cone with the standard light con

Risk Management for Nonprofits

Our research, based on the first comprehensive financial analysis of New York's nonprofit sector, found that 10% of the city's nonprofits were insolvent and 40% had virtually no cash reserves. Less than 30% were financially strong. If anything, things are getting harder, given market volatility, the move to value-based payments in health care, and increased costs for real estate and labor.Fortunately, we also discovered that nonprofits can take a few concrete steps to reduce their risk of failure and sustain vital programs:Make risk management an explicit responsibility of the audit and/or finance committee.Develop a risk-tolerance statement, indicating the limits for risk-taking and the willingness to trade short-term impact for longer-term sustainability.Keep a running list of major risks and the likelihood and expected loss for each.Put in place plans for how to maintain service in the event of a financial disaster, or even a "living will" that specifies how programs will be transferred to other providers (or wound down in an orderly fashion) in the event that recovery is not possible.Brief trustees regularly about longer-term trends in the operating environment.Periodically explore the potential benefits of various forms of organizational redesign, such as mergers, acquisitions, joint ventures, partnerships, outsourcing, managed dissolutions, and divestments.Compare financial performance to peers on an annual basis.Develop explicit targets for operating results (margins, months of cash, etc.) and contingency plans if minimum targets are not met.Redouble efforts to build and safeguard a financial cushion or "rainy-day fund," even if doing so forces consideration of difficult programmatic trade-offs.Doing any of these will depend on a functioning partnership between capable management and a critical mass of experienced, educated and engaged board members. Therefore, organizations serious about risk management must work hard to recruit board members with a wide range of experience. They need to ensure ongoing education for both new and existing board members and to empower high-functioning committees. Many organizations, particularly large and complex ones, would also benefit from having an experienced nonprofit executive on their board

Lieb-Robinson and the butterfly effect

As experiments are increasingly able to probe the quantum dynamics of systems with many degrees of freedom, it is interesting to probe fundamental bounds on the dynamics of quantum information. We elaborate on the relationship between one such bound---the Lieb-Robinson bound---and the butterfly effect in strongly-coupled quantum systems. The butterfly effect implies the ballistic growth of local operators in time, which can be quantified with the "butterfly" velocity $v_B$. Similarly, the Lieb-Robinson velocity places a state independent ballistic upper bound on the size of time evolved operators in non-relativistic lattice models. Here, we argue that $v_B$ is a state-dependent effective Lieb-Robinson velocity. We study the butterfly velocity in a wide variety of quantum field theories using holography and compare with free particle computations to understand the role of strong coupling. We find that, depending on the way length and time scale, $v_B$ acquires a temperature dependence and decreases towards the IR. We also comment on experimental prospects and on the relationship between the butterfly velocity and signaling.Comment: 5+5 pages, 0 figures. v2: updated references and additional clarification

Systematic Physics Constrained Parameter Estimation of Stochastic Differential Equations

A systematic Bayesian framework is developed for physics constrained parameter inference ofstochastic differential equations (SDE) from partial observations. The physical constraints arederived for stochastic climate models but are applicable for many fluid systems. A condition isderived for global stability of stochastic climate models based on energy conservation. Stochasticclimate models are globally stable when a quadratic form, which is related to the cubic nonlinearoperator, is negative definite. A new algorithm for the efficient sampling of such negative definite matrices is developed and also for imputing unobserved data which improve the accuracy of theparameter estimates. The performance of this framework is evaluated on two conceptual climatemodels