Momentum modes of M5-branes in a 2d space

We study M5 branes by considering the selfdual strings parallel to a plane. With the internal oscillation frozen, each selfdual string gives a 5d SYM field. All selfdual strings together give a 6d field with 5 scalars, 3 gauge degrees of freedom and 8 fermionic degrees of freedom in adjoint representation of U(N). Selfdual strings with the same orientation have the SYM-type interaction. For selfdual strings with the different orientations, which could also be taken as the unparallel momentum modes of the 6d field on that plane or the (p,q) (r,s) strings on D3 with (p,q)\neq (r,s), the [i,j]+[j,k]\rightarrow [i,k] relation is not valid, so the coupling cannot be written in terms of the standard N \times N matrix multiplication. 3-string junction, which is the bound state of the unparallel [i,j] [j,k] selfdual strings, may play a role here.Comment: 37 pages, 5 figures, to appear in JHEP; v2: reference adde

The Role of the IMF in Future Sovereign Debt Restructurings: Report of the Annenberg House Expert Group

A meeting of international finance and insolvency experts was held on November 2, 2013 at the Annenberg House in Santa Monica, California. The meeting was co-hosted by the USC Law School and the Annenberg Retreat at Sunnylands. The goal was to solicit the views of experts on the implications of the IMF’s April 26, 2013 paper captioned “Sovereign Debt Restructuring -- Recent Developments and Implications for the Fund’s Legal and Policy Framework”. The April 26 paper may signal a shift in IMF policies in the area of sovereign debt workouts. Although the Expert Group discussed a number of the ideas contained in the April 26 paper, attention focused on paragraph 32 of that paper. That paragraph states in relevant part: “There may be a case for exploring additional ways to limit the risk that Fund resources will simply be used to bail out private creditors. For example, a presumption could be established that some form of a creditor bail-in measure would be implemented as a condition for Fund lending in cases where, although no clear-cut determination has been made that the debt is unsustainable, the member has lost market access and prospects for regaining market access are uncertain.” This Report summarizes the consensus views of the Expert Group on the practical implications of the suggestions contained in paragraph 32 of the April 26 paper

PROMIS Physical Function and Pain Interference scores correlate with the Lower Extremity Toronto Extremity Salvage Score

UNLABELLED: The Toronto Extremity Salvage Score (TESS) and the National Institutes of Health Patient-Reported Outcomes Measurement Information System (PROMIS) are both utilized to measure patient-reported outcomes in adults with musculoskeletal oncologic conditions. However, the relationship between them has not been studied. We sought to describe a link between Lower Extremity (LE) TESS and PROMIS Physical Function (PF) scores, as well as between LE TESS and Pain Interference (PI) scores, to develop a method for converting scores between TESS and PROMIS and to examine whether TESS and PROMIS captured differences in pain and function between clinically relevant subgroups in our population. METHODS: Our study population consisted of 125 adult patients who underwent surgical treatment of a lower-extremity musculoskeletal tumor at a single sarcoma center between December 2015 and October 2018. The LE TESS questionnaire was administered to patients via paper and the PROMIS PF and PI were administered via iPad at a preoperative appointment. The relationship between LE TESS and PROMIS measures was analyzed with use of generalized linear modeling. Subgroup analyses were performed with a 2-tailed t test or 1-way analysis of variance. RESULTS: PROMIS PF had a very strong positive correlation with LE TESS (r = 0.83) and was related through the following equation: CONCLUSIONS: LE TESS and PROMIS PF appeared to measure similar information in patients with an orthopaedic oncologic condition. Moreover, PROMIS PI scores were strongly correlated with functional disability as measured with the LE TESS. Understanding the relationship between TESS and PROMIS will allow the comparison and combination of data for both clinical and research purposes. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence

5-dim Superconformal Index with Enhanced En Global Symmetry

The five-dimensional $\mathcal{N}=1$ supersymmetric gauge theory with Sp(N) gauge group and SO(2N_f) flavor symmetry describes the physics on N D4-branes with $N_f$ D8-branes on top of a single O8 orientifold plane in Type I' theory. This theory is known to be superconformal at the strong coupling limit with the enhanced global symmetry $E_{N_f+1}$ for $N_f\le 7$. In this work we calculate the superconformal index on $S^1\times S^4$ for the Sp(1) gauge theory by the localization method and confirm such enhancement of the global symmetry at the superconformal limit for $N_f\le 5$ to a few leading orders in the chemical potential. Both perturbative and (anti)instanton contributions are present in this calculation. For $N_f=6,7$ cases some issues related the pole structure of the instanton calculation could not be resolved and here we could provide only some suggestive answer for the leading contributions to the index. For the Sp(N) case, similar issues related to the pole structure appear.Comment: 70 pages, references added, published versio

Symmetries of Abelian Orbifolds

Using the Polya Enumeration Theorem, we count with particular attention to C^3/Gamma up to C^6/Gamma, abelian orbifolds in various dimensions which are invariant under cycles of the permutation group S_D. This produces a collection of multiplicative sequences, one for each cycle in the Cycle Index of the permutation group. A multiplicative sequence is controlled by its values on prime numbers and their pure powers. Therefore, we pay particular attention to orbifolds of the form C^D/Gamma where the order of Gamma is p^alpha. We propose a generalization of these sequences for any D and any p.Comment: 75 pages, 13 figures, 30 table

Compactification on negatively curved manifolds

We show that string/M theory compactifications to maximally symmetric space-times using manifolds whose scalar curvature is everywhere negative, must have significant warping, large stringy corrections, or both.Comment: 18 pages, JHEP3.cl

DLCQ String Spectrum from N=2{\cal N}=2 SYM Theory

We study non planar corrections to the spectrum of operators in the ${\mathcal N}=2$ supersymmetric Yang Mills theory which are dual to string states in the maximally supersymmetric pp-wave background with a {\em compact} light-cone direction. The existence of a positive definite discrete light-cone momentum greatly simplifies the operator mixing problem. We give some examples where the contribution of all orders in non-planar diagrams can be found analytically. On the string theory side this corresponds to finding the spectrum of a string state to all orders in string loop corrections.Comment: 35 pages, no figure