Cosmological Constant and Axions in String Theory

String theory axions appear to be promising candidates for explaining cosmological constant via quintessence. In this paper, we study conditions on the string compactifications under which axion quintessence can happen. For sufficiently large number of axions, cosmological constant can be accounted for as the potential energy of axions that have not yet relaxed to their minima. In compactifications that incorporate unified models of particle physics, the height of the axion potential can naturally fall close to the observed value of cosmological constant.Comment: 22 page

Teaching literacy during student teaching : a multicase study of asset-based and humanizing teaching

This study focused on alternative ways of seeing students and engaging in asset-based and humanizing teaching pedagogies, what I call asset-based and humanizing stances, in teacher education. I argue that preservice teachers need experiences to construct students from a lens of what they “can” do and to design teaching pedagogies that focus on students’ assets. Two research questions guided this study: (1) What are the contexts of the student teaching classroom and how do they influence preservice teachers’ asset-based and humanizing pedagogies during student teaching? and (2) How do preservice teachers’ pedagogical enactments exemplify asset-based and humanizing stances of students? Drawing on multicase study design, this qualitative study explored the literacy teaching of three preservice teachers over the course of student teaching, the ways they drew on asset-based and humanizing of their students and the challenges they encountered. Data collection for this study took place during the final two semesters of the preservice teachers’ certification program. Data sources included: ethnographic field notes of literacy events, video and audio recordings of literacy teaching, classroom artifacts, semi-structured interviews, and informal conversations. In the findings, I discuss four asset-based and humanizing teaching pedagogies that were evident in the participants’ teaching enactments: positioning students as knowledgeable others; working to build community within the student teaching setting; using an inquirer’s stance to approach teaching; and teaching based on experiences with students. Then, in a cross-case analysis, I share how the preservice teachers’ teaching enactments exemplified their asset-based and humanizing stances towards students. This analysis suggests that student teaching is a generative space for preservice teachers to learn about students and enact asset-based and humanizing stances, illuminating the power of context and its influence on preservice teachers’ teaching.Curriculum and Instructio

On Nonperturbative Exactness of Konishi Anomaly and the Dijkgraaf-Vafa Conjecture

In this paper we study the nonperturbative corrections to the generalized Konishi anomaly that come from the strong coupling dynamics of the gauge theory. We consider U(N) gauge theory with adjoint and Sp(N) or SO(N) gauge theory with symmetric or antisymmetric tensor. We study the algebra of chiral rotations of the matter field and show that it does not receive nonperturbative corrections. The algebra implies Wess-Zumino consistency conditions for the generalized Konishi anomaly which are used to show that the anomaly does not receive nonperturbative corrections for superpotentials of degree less than 2l+1 where 2l=3c(Adj)-c(R) is the one-loop beta function coefficient. The superpotentials of higher degree can be nonperturbatively renormalized because of the ambiguities in the UV completion of the gauge theory. We discuss the implications for the Dijkgraaf-Vafa conjecture.Comment: 23 page

Low Energy Effective Action in N=2 Yang-Mills as an Integrated Anomaly

Based on chiral ring relations and anomalies, as described by Cachazo, Douglas, Seiberg and Witten, we argue that the holomorphic effective action in N=2 Yang-Mills theory can be understood as an integrated U(1) anomaly from a purely field theory point of view. In particular, we show that the periods of the Riemann surface arising from the generalized Konishi anomaly can be given a physical interpretation without referring to special geometry. We also discuss consequences for the multi-instanton calculus in N=2 Yang-Mills theory.Comment: 25 pages, 2 figures ; v2: reference adde

Moving from Inaction to Action: Challenging Homo- and Transphobia in Middle School English Language Arts

What happens when teachers have opportunities to engage in LGBTQ-affirming practices but choose not to? In the following paper, the authors present a vignette from a middle school context and consider ways to challenge silences to support LGBTQ students in middle school English classrooms. The authors provide discussion and resources to help teachers engage in LGBTQ affirming practices with middle school students

Chiral Rings, Vacua and Gaugino Condensation of Supersymmetric Gauge Theories

We find the complete chiral ring relations of the supersymmetric U(N) gauge theories with matter in adjoint representation. We demonstrate exact correspondence between the solutions of the chiral ring and the supersymmetric vacua of the gauge theory. The chiral ring determines the expectation values of chiral operators and the low energy gauge group. All the vacua have nonzero gaugino condensation. We study the chiral ring relations obeyed by the gaugino condensate. These relations are generalizations of the formula $S^N=\Lambda^{3N}$ of the pure ${\cal N} =1$ gauge theory.Comment: 38 page