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Starting with a gentle approach to the AGT correspondence from its 6d origin, these notes provide a wide (albeit shallow) survey of the literature on numerous extensions of the correspondence up to early 2020. This is an extended writeup of the lectures given at the Winter School YRISW 2020, to appear in a special issue of JPhysA. Class S is a wide class of 4d $N=2$ supersymmetric gauge theories (ranging from super-QCD to non-Lagrangian theories) obtained by twisted compactification of 6d $N=(2,0)$ superconformal theories on a Riemann surface. This 6d construction yields the Coulomb branch and Seiberg-Witten geometry of class S theories, geometrizes S-duality, and leads to the AGT correspondence, which states that many observables of class S theories are equal to 2d CFT correlators. For instance, the four-sphere partition function of a 4d $N=2$ SU(2) superconformal quiver theory is equal to a Liouville CFT correlator of primary operators. Extensions of the AGT correspondence abound: asymptotically-free gauge theories and Argyres-Douglas theories correspond to irregular CFT operators, quivers with higher-rank gauge groups and non-Lagrangian tinkertoys such as $T_N$ correspond to Toda CFT correlators, and nonlocal operators (Wilson-'t Hooft loops, surface operators, domain walls) correspond to Verlinde networks, degenerate primary operators, braiding and fusion kernels, and Riemann surfaces with boundaries., Comment: 106 pages plus 1309 refs. Published version

Cosmological bounces occur in many gravity theories. We define singularity scattering maps relating large scale geometries before and after the bounce (assuming no BKL oscillations) and encoding microscopic details of the theory. By classifying all suitably local maps we uncover three universal laws: scaling of Kasner exponents, canonical transformation of matter, directional metric scaling. These are indeed obeyed by Bianchi I bounces in string theory, loop quantum cosmology and modified matter models; our classification then determines how inhomogeneities and anisotropies traverse bounces, and precisely extracts model-dependent degrees of freedom., Comment: 6 pages; updated presentation of the three laws

For spacetimes containing quiescent singularity hypersurfaces we propose a general notion of junction conditions based on a prescribed singularity scattering map, as we call it, and we introduce the notion of a cyclic spacetime (also called a multiverse) consisting of spacetime domains bounded by spacelike or timelike singularity hypersurfaces, across which our scattering map is applied. A local existence theory is established here while, in a companion paper, we construct plane-symmetric cyclic spacetimes. We study the singularity data space consisting of the suitably rescaled metric, extrinsic curvature, and matter fields which can be prescribed on each side of the singularity, and for the class of so-called quiescent singularities we establish restrictions that a singularity scattering map must satisfy. We obtain a full characterization of all scattering maps that are covariant and ultralocal, in a sense we define and, in particular, we distinguish between, on the one hand, three laws of bouncing cosmology of universal nature and, on the other hand, model-dependent junction conditions. The theory proposed in this paper applies to spacelike and timelike hypersurfaces and without symmetry restriction. It encompasses bouncing-cosmology scenarios, both in string theory and in loop quantum cosmology, and puts strong restrictions on their possible explicit realizations., Comment: 54 pages. v2: Construction of plane-symmetric cyclic spacetimes moved to arXiv:2106.09666. v3: Version published in JHEP

Postural stability is linked to vision in everyone, since when the eyes are closed stability decreases by a factor of 2 or more. However, in persons with dyslexia postural stability is often deficient even when the eyes are open, since they show deficits in motor as well as specific cognitive functions. In dyslexics we have shown that abnormal symmetry between retinal Maxwell's centroid outlines occurs, perturbing the interhemispheric connections. We have also shown that pulse-width modulated lighting can compensate for this lack of asymmetry, improving the reading skills. As the postural stability and the vision are correlated, one may wonder if the excess of the postural instability recorded in a young adult with dyslexia can also be reduced by a pulse-width modulated light controlling the Hebbian synaptic plasticity. Using a force platform we compared the postural responses of an observer without dyslexia with the responses of a subject with dyslexia, by measuring their respective standing postures with eyes open looking at a target in a room with either continuous or pulse lighting. There was no effect of changing the lighting conditions on the postural control of the subject without dyslexia. However, we found that the postural stability of the subject with dyslexia which was actually impaired during continuous light, but was greatly improved when a 80 Hz pulsed light frequency was used. Importantly, the excursions of the surface area of the center of pressure on the force platform were reduced by a factor of 2.3., Comment: 9 pages, 6 figures

The original purpose of the Title I program of the "Elementary and Secondary Education Act of 1965" (ESEA) was to provide supplemental services to assist low-achieving students in high-poverty schools, and schools were required to target Title I funds specifically to serve such students. In 1978, the schoolwide program (SWP) option was introduced to provide high-poverty schools with the flexibility to use Title I funds for whole-school approaches to improving achievement for all students in schools with high concentrations of poverty, particularly low-achieving students. Unlike schools using the traditional targeted assistance program (TAP) approach, SWP schools are allowed to consolidate Title I funds with those from other federal, state, and local sources and are not required to ensure that the funds are spent only for specific students identified as low achieving. This study examined how SWPs use their flexibility to design schoolwide services and strategies to address the needs of students who are low achieving and compare these practices with those used by TAP schools. Specifically, the data collected for this study provide insight into the types of services that are supported by Title I funds in SWP and TAP schools, the decision-making processes that inform the use of funds, and the extent to which Title I funds are consolidated or coordinated with other funding sources to support improved student outcomes. [For the results in brief, see ED613345.]

We consider the Einstein equations in T2 symmetry, either for vacuum spacetimes or coupled to the Euler equations for a compressible fluid, and we introduce the notion of T2 areal flows on T3 with finite total energy. By uncovering a hidden structure of the Einstein equations, we establish a compensated compactness framework and solve the global evolution problem for vacuum spacetimes as well as for self-gravitating compressible fluids. We study the stability and instability of such flows and prove that, when the initial data are well-prepared, any family of T2 areal flows is sequentially compact in a natural topology. In order to handle general initial data we propose a relaxed notion of T2 areal flows endowed with a corrector stress tensor (as we call it) which is a bounded measure generated by geometric oscillations and concentrations propagating at the speed of light. This generalizes a result for vacuum spacetimes in: Le Floch B. and LeFloch P.G., Arch. Rational Mech. Anal. 233 (2019), 45-86. In addition, we determine the global geometry of the corresponding future Cauchy developments and we prove that the area of the T2 orbits generically approaches infinity in the future-expanding regime. In the future-contracting regime, the volume of the T3 spacelike slices approaches zero and, for generic initial data, the area of the orbits of symmetry approaches zero in Gowdy symmetric matter spacetimes and in T2 vacuum spacetimes., Comment: 6 pages

We present a new strategy to optimise the electromagnetic follow-up of gravitational wave triggers. This method is based on the widely used galaxy targeting approach where we add the stellar mass of galaxies in order to prioritise the more massive galaxies. We crossmatched the GLADE galaxy catalog with the AllWISE catalog up to 400Mpc with an efficiency of $\sim$93\%, and derived stellar masses using a stellar-to-mass ratio using the WISE1 band luminosity. We developed a new grade to rank galaxies combining their 3D localisation probability associated to the gravitational wave event with the new stellar mass information. The efficiency of this new approach is illustrated with the GW170817 event, which shows that its host galaxy, NGC4993, is ranked at the first place using this new method. The catalog, named Mangrove, is publicly available and the ranking of galaxies is automatically provided through a dedicated web site for each gravitational wave event.

The concept of geometrical frustration in condensed matter physics refers to the fact that a system has a locally preferred structure with an energy density lower than the infinite ground state. This notion is however often used in a qualitative sense only. In this article, we discuss a quantitative definition of geometrical frustration in the context of lattice models of binary spins. To this aim, we introduce the framework of local energy landscapes, within which frustration can be quantified as the discrepancy between the energy of locally preferred structures and the ground state. Our definition is scale-dependent and involves an optimization over a gauge class of equivalent local energy landscapes, related to one another by local energy displacements. This ensures that frustration depends only on the physical Hamiltonian and its range, and not on unphysical choices in how it is written. Our framework shows that a number of popular frustrated models, including the antiferromagnetic Ising model on a triangular lattice, only have finite-range frustration: geometrical incompatibilities are local and can be eliminated by an exact coarse-graining of the local energies.

Two-dimensional CFTs and integrable models have an infinite set of conserved KdV higher spin currents. These currents can be argued to remain conserved under the $T\bar{T}$ deformation and its generalizations. We determine the flow equations the KdV charges obey under the $T\bar{T}$ deformation: they behave as probes "riding the Burgers flow" of the energy eigenvalues. We also study a Lorentz-breaking $T_{s+1}\bar{T}$ deformation built from a KdV current and the stress tensor, and find a super-Hagedorn growth of the density of states., Comment: 39 pages. v2: references added, version published in SciPost

We study superconformal deformations of the $T_\rho^{\hat\rho}[SU(N)]$ theories of Gaiotto-Hanany-Witten, paying special attention to mixed-branch operators with both electrically- and magnetically-charged fields. We explain why all marginal ${\cal N}=2$ operators of an ${\cal N}=4$ CFT$_3$ can be extracted unambiguously from the superconformal index. Computing the index at the appropriate order we show that the mixed moduli in $T_\rho^{\hat\rho}[SU(N)]$ theories are double-string operators transforming in the (Adjoint, Adjoint) representation of the electric and magnetic flavour groups, up to some overcounting for quivers with abelian gauge nodes. We comment on the holographic interpretation of the results, arguing in particular that gauged supergravities can capture the entire moduli space if, in addition to the (classical) parameters of the background solution, one takes also into account the (quantization) moduli of boundary conditions., Comment: 35 pages. v3: published version (more explicit formulas)

We deform two-dimensional quantum field theories by antisymmetric combinations of their conserved currents that generalize Smirnov and Zamolodchikov's $T\bar{T}$ deformation. We obtain that energy levels on a circle obey a transport equation analogous to the Burgers equation found in the $T\bar{T}$ case. This equation relates charges at any value of the deformation parameter to charges in the presence of a (generalized) Wilson line. We determine the initial data and solve the transport equations for antisymmetric combinations of flavor symmetry currents and the stress tensor starting from conformal field theories. Among the theories we solve is a conformal field theory deformed by $J\bar{T}$ and $T\bar{T}$ simultaneously. We check our answer against results from AdS/CFT., Comment: 42 pages

Background/significance: Standards-based accountability systems have been a pillar of education reform in the United States for almost three decades. Although accountability systems have evolved in progressive reauthorizations of the Elementary and Secondary Education Act (ESEA), the underlying theory of action has changed little. The basic premise is that school-level accountability designations signal low (and high) levels of student performance or school quality, provide meaningful information to local stakeholders about actionable areas in which schools are underperforming, and motivate educators to foster improvements in student outcomes (Elmore, 2004; Hanushek & Raymond, 2001; National Research Council, 2011; O'Day, 2002; Saw et al., 2017). In December 2015, ESEA was reauthorized as the Every Student Succeeds Act (ESSA), which made several key changes to federal accountability policy. A key feature of ESSA is its flexibility, as it gave states substantial latitude in designing their processes for identifying and providing supports to low-performing schools (i.e., comprehensive support and improvement [CSI] schools). The current policy context promotes increasingly complex accountability systems with multiple measures and varied ways of calculating school performance, while also providing states, districts, and schools with more flexibility regarding how they will address low performance. Increased complexity and flexibility mean that school leaders must weigh more information and make strategic decisions about which accountability measures to prioritize and what improvement strategies to use in response to accountability results. Although several recent meta-analyses suggest that on average school performance improves in schools identified as low-performing in ESSA-style accountability systems, there is substantial heterogeneity in results with some systems being successful and others potentially harming low-performing schools (Redding & Nguyen, 2020; Schueler et al., 2020). Despite 25 years of federal accountability policies, many questions still exist about their ability to spur broad improvement, and notable gaps exist in our understanding of how accountability systems work, particularly in the context of the ESSA reauthorization. Purpose/Research Questions: In this study, we examine the causal effects of CSI designation on student outcomes including test scores, suspensions, absenteeism, high school graduation, and other student outcomes that are used for school accountability purposes. We also examine some of the mechanisms that might be driving the observed effects such as student mobility and teacher attrition. Setting: We have partnered with three states to conduct analyses of CSI schools: California, Ohio, and Florida. These three states represent different approaches to accountability and three different state contexts. In California, CSI schools are identified based on a series of business rules, where each accountability "indicator" is assigned a color (red being the lowest performing and blue being the highest performing). Schools with a sufficient number or percentage of red and orange indicators are identified as CSI. Both Ohio and Florida use index-based approaches for identifying CSI schools, where a variety of accountability measures are aggregated based on weights assigned to each measure. Schools with a low enough "index" are identified as CSI. Population/Sample: The population consists of all schools in our three partner states. Specifically, as of 2019-20, California had approximately 750 CSI schools, Florida had approximately 440 CSI schools, and Ohio had approximately 230 CSI schools. Intervention: Under ESSA, each state is required to identify at least the bottom 5% of schools based on performance and high schools with graduation rates below 67% to be identified as CSI schools. These schools are then intended to receive some additional funding, be provided additional supports, develop plans for improvement, implement strategies to improve, and ultimately improve student outcomes. Under ESSA, states were provided more flexibility to determine how to intervene in CSI schools and which improvement strategies to emphasize. Although not included in this paper, we conducted a principal survey and district interviews to better understand approaches to improvement and supports provided to CSI schools. Data sources and methods: To investigate the effects of the CSI designation on student outcomes, we obtained student- and school-level data from three states. Outcome data in each state consist of student-level test scores in math and ELA, attendance rates, student discipline, and graduation. The three states also provided student-level demographic data including student race, economic disadvantage status, special education status, and English learner status. We paired student-level data with data on CSI designation in 2018-19 and subsequent years. Using this data, we used two approaches to examine the effects of CSI designation on student outcomes. First, we used regression discontinuity (RD) to investigate the effect of CSI designation around school performance cutoffs. Because both Ohio and Florida both use an aggregate school performance index where schools performing below a cutoff are designated as CSI schools, the RD approach is most straightforward in these states. In California, a series of cutoffs on each individual indicator are used to determine performance ratings on each indicator. Given that no single cutoff determines CSI status, we used a comparative interrupted time series approach for California that establishes performance trends in both CSI and non-CSI schools prior to initial designation and then compares the difference in trends for both school types in the post-identification time periods. However, we have also used RD in California to understand the effect of earning a red or orange color on a given indicator. Findings: Preliminary results from Ohio through four years after CSI designation (2018-19 through 2021-22) using RD show no statistically significant improvements in student outcomes for CSI schools relative to non-CSI schools and several areas were CSI schools performed worse than non-CSI schools, including graduation rates, attendance, and ACT test scores. We are working on developing potential explanations for these findings. We are also working on completing analyses for California and Florida.

We study how B-branes in two-dimensional N=(2,2) anomalous models behave as we vary the energy scale and bulk parameters in the quantum K\"ahler moduli space. We focus on (2,2) theories defined by abelian gauged linear sigma models (GLSM). Guided by the hemisphere partition function we find how B-branes split in arbitrary phases into components on the Higgs branch and other branches: this generalizes the band restriction rules of Herbst-Hori-Page to (abelian) anomalous models. Secondly, we address divergences in non-compact models, through the central example of GLSMs for Hirzebruch-Jung resolutions of cyclic surface singularities. For a brane with compact support we explain how to regularize and compute the hemisphere partition function and extract its Higgs branch component, which we match in the zero-instanton sector to the geometric central charge of the brane. To this aim, we clarify the definition of zero-instanton geometric central charge for objects in the derived category of a non-compact toric orbifold., Comment: 83 pages. New calculations in section 5 for partially-resolved orbifold singularities. More explicit introduction, clearer section 6 and improved references. To appear in the Beijing Journal of Pure and Applied Mathematics (BPAM)

Semitoric systems are a type of four-dimensional integrable system for which one of the integrals generates a global $S^1$-action; these systems were classified by Pelayo and Vu Ngoc in terms of five symplectic invariants. We introduce and study semitoric families, which are one-parameter families of integrable systems with a fixed $S^1$-action that are semitoric for all but finitely many values of the parameter, with the goal of developing a strategy to find a semitoric system associated to a given partial list of semitoric invariants. We also enumerate the possible behaviors of such families at the parameter values for which they are not semitoric, providing examples illustrating nearly all possible behaviors, which describes the possible limits of semitoric systems with a fixed $S^1$-action. Furthermore, we introduce natural notions of blowup and blowdown in this context, investigate how semitoric families behave under these operations, and use this to prove that each Hirzebruch surface admits a semitoric family with certain desirable invariants; these families are related to the semitoric minimal model program. Finally, we give several explicit semitoric families on the first and second Hirzebruch surfaces showcasing various possible behaviors of such families which include new semitoric systems., Comment: Updated to version accepted by the Memoirs of the AMS, added references and improved exposition. 96 pages and 34 figures

For any simple complex Lie group we classify irreducible finite-dimensional representations $\rho$ for which the longest element $w_0$ of the Weyl group acts nontrivially on the zero weight space. Among irreducible representations that have zero among their weights, $w_0$ acts by $\pm$Id if and only if the highest weight of $\rho$ is a multiple of a fundamental weight, with a coefficient less than a bound that depends on the group and on the fundamental weight., Comment: 20 pages. This version has two appendixes that did not appear in the published version. The first appendix contains the full list of the results of the computations done "by hand", and the second appendix contains the computer code used to do these computations

We are interested in the evolution of a compressible fluid under its self-generated gravitational field. Assuming here Gowdy symmetry, we investigate the algebraic structure of the Euler equations satisfied by the mass density and velocity field. We exhibit several interaction functionals that provide us with a uniform control on weak solutions in suitable Sobolev norms or in bounded variation. These functionals allow us to study the local regularity and nonlinear stability properties of weakly regular fluid flows governed by the Euler-Gowdy system. In particular for the Gowdy equations, we prove that a spurious matter field arises under weak convergence, and we establish the nonlinear stability of weak solutions., Comment: 37 pages. v2: fix typos to match version published in 2019

We follow existing distributed systems frameworks employing methods from algebraic topology to formally define primitives of blockchain technology. We define the notion of cross chain liquidity, sharding and probability spaces between and within blockchain protocols. We incorporate recent advancements in synthetic homology to show that this topological framework can be implemented within a type system. We use recursion schemes to define kernels admitting smooth manifolds across protocol complexes, leading to the formal definition of a Poincare protocol.

The ferroelectric phase transition temperature of a single crystal $SrTiO_3$ cylindrical puck inserted into a cylindrical copper cavity has been measured around $51~K$ using quasi $TE_{m,1,1}$ and quasi $TM_{m,1,1}$ electromagnetic modes. The observed results of such dielectric spectroscopy may be explained by implementing a quasiharmonic approximation of phonons in the incipient ferroelectric crystal $SrTiO_3$ lattice. The resonant modes act as very sensitive probe by implementing measurements of $Q$-factor, transmission or frequency shift when cooling down to low temperatures around a few Kelvin. The resonator dielectric losses reveals different crystal unit structure states and ferroelectric phase transition in continuous cooling. The ferroelectric phase transition initiates a spontaneous polarization $(P_s)$ forming a double-well potential in each crystal unit causing a two-level systems, which creates extra loss and changes the transmission characteristics and Q-factors of the modes. This process is able to describe resonator properties over a broad range of frequency. Landau's theory of correlation length supports the reported observations as the implication of phonon wave vector $q_c=0$ of central ion in crystal unit symmetry regarding soft-mode., Comment: Typos fixed

THESEUS is a space mission concept aimed at exploiting Gamma-Ray Bursts for investigating the early Universe and at providing a substantial advancement of multi-messenger and time-domain astrophysics. These goals will be achieved through a unique combination of instruments allowing GRB and X-ray transient detection over a broad field of view (more than 1sr) with 0.5-1 arcmin localization, an energy band extending from several MeV down to 0.3 keV and high sensitivity to transient sources in the soft X-ray domain, as well as on-board prompt (few minutes) follow-up with a 0.7 m class IR telescope with both imaging and spectroscopic capabilities. THESEUS will be perfectly suited for addressing the main open issues in cosmology such as, e.g., star formation rate and metallicity evolution of the inter-stellar and intra-galactic medium up to redshift $\sim$10, signatures of Pop III stars, sources and physics of re-ionization, and the faint end of the galaxy luminosity function. In addition, it will provide unprecedented capability to monitor the X-ray variable sky, thus detecting, localizing, and identifying the electromagnetic counterparts to sources of gravitational radiation, which may be routinely detected in the late '20s / early '30s by next generation facilities like aLIGO/ aVirgo, eLISA, KAGRA, and Einstein Telescope. THESEUS will also provide powerful synergies with the next generation of multi-wavelength observatories (e.g., LSST, ELT, SKA, CTA, ATHENA)., Comment: Accepted for publication in Advances in Space Research. Partly based on the proposal submitted on October 2016 in response to the ESA Call for next M5 mission, with expanded and updated science sections

We relate Liouville/Toda CFT correlators on Riemann surfaces with boundaries and cross-cap states to supersymmetric observables in four-dimensional N=2 gauge theories. Our construction naturally involves four-dimensional theories with fields defined on different Z$_2$ quotients of the sphere (hemisphere and projective space) but nevertheless interacting with each other. The six-dimensional origin is a Z$_2$ quotient of the setup giving rise to the usual AGT correspondence. To test the correspondence, we work out the RP$^4$ partition function of four-dimensional N=2 theories by combining a 3d lens space and a 4d hemisphere partition functions. The same technique reproduces known RP$^2$ partition functions in a form that lets us easily check two-dimensional Seiberg-like dualities on this nonorientable space. As a bonus we work out boundary and cross-cap wavefunctions in Toda CFT., Comment: 56 pages. v2: Clarify discrete theta angle. v3: Published in JHEP; extra references. v4: Minor sign fix; extra references

We define mixed states associated with submanifolds with probability densities in quantizable closed K{\"a}hler manifolds. Then, we address the problem of comparing two such states via their fidelity. Firstly, we estimate the sub-fidelity and super-fidelity of two such states, giving lower and upper bounds for their fidelity, when the underlying submanifolds are two Lagrangian submanifolds intersecting transversally at a finite number of points, in the semiclassical limit. Secondly, we investigate a family of examples on the sphere, for which we manage to obtain a better upper bound for the fidelity. We conclude by stating a conjecture regarding the fidelity in the general case., Comment: Structure of the paper revised to improve exposition

The Study of School Turnaround (SST) examines the change process in a diverse, purposive sample of schools receiving federal School Improvement Grants (SIG) from 2010-11 to 2012-13. With the passage of the American Recovery and Reinvestment Act of 2009 (ARRA), the SIG program underwent three major shifts. First, ARRA boosted total SIG funding in fiscal year 2009 to approximately 6.5 times the original 2009 appropriation through Title I, section 1003(g) of the Elementary and Secondary Education Act (ESEA). SIG funds were distributed to states by formula based on each state's Title I share. States then had to competitively make SIG awards to districts with eligible schools. Second, ARRA targeted funds at only the very worst schools--those that were in the bottom 5 percent of performance and had been low performing for an extended period of time. Third, schools receiving SIG were now required to implement one of four prescriptive intervention models believed to be more aggressive and comprehensive than those generally adopted under prior policies. By increasing the level of funding, better targeting these funds to the persistently lowest-achieving schools, and requiring that schools adopt specific intervention models, the revamped SIG program aimed to catalyze more aggressive efforts to turn around student performance. This report focuses on a small sample of schools receiving SIG over the first three years of the revamped SIG program, from 2010-11 to 2012-13. It presents findings from the study's 25 core sample schools, which were the focus of data collection in spring 2011 and spring 2012, and a subsample of 12 of the 25 schools (collectively referred to as the core subsample), which were selected for data collection in spring 2013 and are the focus of more in-depth analyses looking across all three years of SIG. The findings include: (1) A majority of the 25 core sample schools replaced their principal (21 schools) at least once in the year before SIG (2009-10) or in Year 1 of SIG (2010-11); (2) About half of the 25 core sample schools (12 schools, including 9 turnaround, 2 restart, and 1 transformation) replaced at least 50 percent of their teachers during the 2009-10, 2010-11, or 2011-12 school years; (3) According to teacher survey data, more teachers reported participating in professional learning on math, literacy, and data use than on ELL instruction, special education, or classroom management during Year 2 of SIG (2011-12); (4) Core sample schools reported receiving support from their district (22 of 22 schools) and external support provider(s) (22 of 25 schools), but in some cases, respondents described shortcomings in their district or external support; (5) Among the 12 core subsample schools, those that appeared to engage in more efforts to build human capital in Years 1 and 2 of SIG (7 schools) were more likely to improve their organizational capacity (or sustain their already higher capacity); and (6) Sustainability of any improvements may prove fragile. The following are appended: (1) Study of School Turnaround Codebook, 2010-13; (2) Technical Approach to Qualitative Analyses; (3) Details of Teacher Survey Analyses; and (4) Leading Indicators of School-Level Capacity.

The Issue: School improvement policy for the past few decades has been characterized by mandated lists of activities--both well intended and research based--designed to stimulate a dramatic turnaround in student achievement. However, this prescriptive approach to policy, particularly federal policy, has not resulted in the systemic changes needed to get the right teachers and leaders into low-performing schools to support school improvement. In the long run, this policy approach did not engender the school-level changes necessary to create learning organizations that support teachers and leaders. The Research: One key lesson from the past decades of school improvement research is that an explicit focus on improving the capacity and stability of teachers and leaders in low-performing schools would benefit these schools more than another mandated checklist of improvement activities. Schools can never be any stronger or more effective than the adults who work in them--doubly true for chronically low-performing schools. The Recommendations: With the passage of the Every Student Succeeds Act (ESSA), state policymakers must prepare for states' increased role in making low-performing schools better. We suggest that policymakers step back from requirements to implement specific improvement activities (similar to those required by the federal School Improvement Grants [SIG] program) and instead focus policy on the development and support of human capital. New policies must aim to get the right people in our schools and to create district and state systems that retain those people and build their knowledge and skills to turn schools around.

The "Elementary and Secondary Education Act of 1965" ("ESEA") is the nation's key policy driver for elementary and secondary education, shaping federal, state and district efforts to promote effective school systems and improve educational outcomes, particularly for students in high-poverty schools. The most recent reauthorization of "ESEA" (the "No Child Left Behind Act of 2001," or "NCLB") called for landmark changes. This report explores the early implementation of state-differentiated recognition, accountability and support systems under the U.S. Department of Education's "ESEA" flexibility initiative, announced in September 2011. "ESEA" flexibility offers states flexibility with regard to how states set annual measurable objectives (AMOs), whether or not they continue to calculate adequate yearly progress (AYP), designate low-performing schools and districts, implement interventions, use section 1003(a) funds, determine transferability of "ESEA" funds and implement improvement plans for highly qualified teachers. The findings are based on telephone interviews conducted with a sample of state, district and school-level officials in late 2013 and early 2014, and a review of relevant policy documents that were available on state and local education agency websites during this same time period. Participants in the state and district sample included officials from 12 state education agencies with approved "ESEA" flexibility requests and 22 districts located within these 12 states. The school-level sample drew from the state and district sample and participants included principals of 25 Title I schools located within a subset of 12 districts and six states. Although the state, district and school samples were diverse, the states, districts and schools were not randomly selected and are not representative of the larger population of 35 states whose "ESEA" flexibility requests had been approved at the time of this study and the districts and schools within these states. Thus, the findings presented in this report are not generalizable. The purpose of this study was to explore state and district processes, successes and challenges, as well as school-level experiences associated with the early implementation of the accountability provisions of "ESEA" flexibility. [For the results in brief, see ED613361.]

We propose a simple formula for the 4d-2d partition function of half-BPS surface defects in $d=4,\ \mathcal{N}=2$ gauge theories: $Z^{\text{4d-2d}}=\langle Z^{\text{2d}} \rangle_{\text{4d}}$. Our results are applicable for any surface defect obtained by gauging a 2d flavour symmetry using a 4d gauge group. For defects obtained via the Higgsing procedure, our formula reproduces the recent calculation by Pan and Peelaers. For Gukov-Witten defects our results reproduce the orbifold calculation by Kanno and Tachikawa. We emphasize the role of "negative vortices" which are realized as negative D0 branes., Comment: v1: 40 pages, 8 figures, v2: clarifications and references added

Dielectric resonators are employed to build state-of-the-art low-noise and high- stability oscillators operating at room and cryogenic temperatures. A resonator temperature coefficient of frequency is one criterion of performance. This paper reports on predictions and measurements of this temperature coefficient of frequency for three types of cylindrically-symmetric Bragg resonators operated at microwave frequencies. At room temperature, microwave Bragg resonators have the best potential to reach extremely high Q-factors. Research has been conducted over the last decade on modeling, optimizing and realizing such high Q-factor devices for applications such as filtering, sensing, and frequency metrology. We present an optimized design, which has a temperature sensitivity 2 to 4 times less than current whispering gallery mode resonators without using temperature compensating techniques and about 30% less than other existing Bragg resonators. Also, the performance of a new generation single-layered Bragg resonators, based on a hybrid-Bragg-mode, is reported with a sensitivity of about -12ppm/K at 295K. For a single reflector resonator, it achieves a similar level of performance as a double-Bragg-reflector resonator but with a more compact structure and performs six times better than whispering-gallery-mode resonators. The hybrid resonator promises to deliver a new generation of high-sensitivity sensors and high-stability room-temperature oscillators., Comment: 24 pages, 8 figures, 2 tables, journal article

To take advantage of the astrophysical potential of Gamma-Ray Bursts (GRBs), Chinese and French astrophysicists have engaged the SVOM mission (Space-based multi-band astronomical Variable Objects Monitor). Major advances in GRB studies resulting from the synergy between space and ground observations, the SVOM mission implements space and ground instrumentation. The scientific objectives of the mission put a special emphasis on two categories of GRBs: very distant GRBs at z$>$5 which constitute exceptional cosmological probes, and faint/soft nearby GRBs which allow probing the nature of the progenitors and the physics at work in the explosion. These goals have a major impact on the design of the mission: the on-board hard X-ray imager is sensitive down to 4 keV and computes on line image and rate triggers, and the follow-up telescopes on the ground are sensitive in the NIR. At the beginning of the next decade, SVOM will be the main provider of GRB positions and spectral parameters on very short time scale. The SVOM instruments will operate simultaneously with a wide range of powerful astronomical devices. This rare instrumental conjunction, combined with the relevance of the scientific topics connected with GRB studies, warrants a remarkable scientific return for SVOM. In addition, the SVOM instrumentation, primarily designed for GRB studies, composes a unique multi-wavelength observatory with rapid slew capability that will find multiple applications for the whole astronomy community beyond the specific objectives linked to GRBs. This report lists the scientific themes that will benefit from observations made with SVOM, whether they are specific GRB topics, or more generally all the issues that can take advantage of the multi-wavelength capabilities of SVOM., Comment: 67 pages, 1 frontispiece, 21 figures. Report on the Scientific prospects of the SVOM mission. Proceedings of the Workshop held from 11th to 15th April 2016 at Les Houches School of Physics, France

We initiate the study of intersecting surface operators/defects in four-dimensional quantum field theories (QFTs). We characterize these defects by coupled 4d/2d/0d theories constructed by coupling the degrees of freedom localized at a point and on intersecting surfaces in spacetime to each other and to the four-dimensional QFT. We construct supersymmetric intersecting surface defects preserving just two supercharges in N = 2 gauge theories. These defects are amenable to exact analysis by localization of the partition function of the underlying 4d/2d/0d QFT. We identify the 4d/2d/0d QFTs that describe intersecting surface operators in N = 2 gauge theories realized by intersecting M2-branes ending on N M5-branes wrapping a Riemann surface. We conjecture and provide evidence for an explicit equivalence between the squashed four-sphere partition function of these intersecting defects and correlation functions in Liouville/Toda CFT with the insertion of arbitrary degenerate vertex operators, which are labeled by representations of SU(N)., Comment: 74 pages, one-column version of the version published in 2017

This is an introductory review to localization techniques in supersymmetric two-dimensional gauge theories. In particular we describe how to construct Lagrangians of N=(2,2) theories on curved spaces, and how to compute their partition functions and certain correlators on the sphere, the hemisphere and other curved backgrounds. We also describe how to evaluate the partition function of N=(0,2) theories on the torus, known as the elliptic genus. Finally we summarize some of the applications, in particular to probe mirror symmetry and other non-perturbative dualities., Comment: This is a contribution to the review volume `Localization techniques in quantum field theories' (eds. V. Pestun and M. Zabzine) which contains 17 Chapters. The complete volume is summarized in arXiv:1608.02952 and it can be downloaded at https://arxiv.org/src/1608.02952/anc/LocQFT.pdf or http://pestun.ihes.fr/pages/LocalizationReview/LocQFT.pdf

This is the foreword to the special volume on localization techniques in quantum field theory. We summarize the individual chapters and their relation., Comment: The complete volume can be downloaded at https://arxiv.org/src/1608.02952/anc/LocQFT.pdf or http://pestun.ihes.fr/pages/LocalizationReview/LocQFT.pdf

We give a detailed study of the symplectic geometry of a family of integrable systems obtained by coupling two angular momenta in a non trivial way. These systems depend on a parameter t $\in$ [0, 1] and exhibit different behaviors according to its value. For a certain range of values, the system is semitoric, and we compute some of its symplectic invariants. Even though these invariants have been known for almost a decade, this is to our knowledge the first example of their computation in the case of a non-toric semitoric system on a compact manifold (the only invariant of toric systems is the image of the momentum map). In the second part of the paper we quantize this system, compute its joint spectrum, and describe how to use this joint spectrum to recover information about the symplectic invariants., Comment: Exposition revised. A problem which affected the computation of one invariant has been fixed

This paper presents a predictive controller for handling plug-and-play (P&P) charging requests of flexible loads in a distribution system. We define two types of flexible loads: (i) deferrable loads that have a fixed power profile but can be deferred in time and (ii) shapeable loads that have flexible power profiles but fixed energy requests, such as Plug-in Electric Vehicles (PEVs). The proposed method uses a hierarchical control scheme based on a model predictive control (MPC) formulation for minimizing the global system cost. The first stage computes a reachable reference that trades off deviation from the nominal voltage with the required generation control. The second stage uses a price-based objective to aggregate flexible loads and provide load shaping services, while satisfying system constraints and users' preferences at all times. It is shown that the proposed controller is recursively feasible under specific conditions, i.e. the flexible load demands are satisfied and bus voltages remain within the desired limits. Finally, the proposed scheme is illustrated on a 55 bus radial distribution network.

We investigate the microwave magnetic field confinement in several microwave 3D-cavities, using 3D finite-element analysis to determine the best design and achieve strong coupling between microwave resonant cavity photons and solid state spins. Specifically, we design cavities for achieving strong coupling of electromagnetic modes with an ensemble of nitrogen vacancy (NV) defects in diamond. We report here a novel and practical cavity design with a magnetic filling factor of up to 4 times (2 times higher collective coupling) than previously achieved using 1D superconducting cavities with small mode volume. In addition, we show that by using a double-split resonator cavity, it is possible to achieve up to 200 times better cooperative factor than the currently demonstrated with NV in diamond. These designs open up further opportunities for studying strong and ultra-strong coupling effects on spins in solids using alternative systems with a wider range of design parameters., Comment: 20 pages, 9 figures