Hasil untuk "hep-th"

Hiroshi Itoyama, Takeshi Oota, Reiji Yoshioka

In the previous letter, arXiv:2210.16738[hep-th], we found a set of flavor mass relations as constraints that the $β$-deformed $A_{n-1}$ quiver matrix model restores the maximal symmetry in the massive scaling limit and reported the existence of Argyres-Douglas critical hypersurface. In this letter, we derive the concrete conditions on moduli parameters which maximally degenerates the Seiberg-Witten curve while maintaining the flavor mass relations. These conditions define the A-D hypersurface.

Luigi Alfonsi

The history of the geometry of Double Field Theory is the history of string theorists' effort to tame higher geometric structures. In this spirit, the first part of this paper will contain a brief overview on the literature of geometry of DFT, focusing on the attempts of a global description. In arXiv:1912.07089 [hep-th] we proposed that the global doubled space is not a manifold, but the total space of a bundle gerbe. This would mean that DFT is a field theory on a bundle gerbe, in analogy with ordinary Kaluza-Klein Theory being a field theory on a principal bundle. In this paper we make the original construction by arXiv:1912.07089 [hep-th] significantly more immediate. This is achieved by introducing an atlas for the bundle gerbe. This atlas is naturally equipped with $2d$-dimensional local charts, where $d$ is the dimension of physical spacetime. We argue that the local charts of this atlas should be identified with the usual coordinate description of DFT. In the last part we will discuss aspects of the global geometry of tensor hierarchies in this bundle gerbe picture. This allows to identify their global non-geometric properties and explain how the picture of non-abelian String-bundles emerges. We interpret the abelian T-fold and the Poisson-Lie T-fold as global tensor hierarchies.

Spyros Basilakos, Nick E. Mavromatos, Joan Sola

We discuss a connection between gravitational-wave physics, quantum theory anomalies, right-handed (sterile) neutrinos, (spontaneous) CPT Violation and Leptogenesis, within the framework of string-inspired cosmological models. In particular, we present a scenario, according to which (primordial) gravitational waves induce gravitational anomalies during inflation. This, in turn, results in the existence of an undiluted (at the exit of inflation/beginning of radiation era) bakcground of the Kalb-Ramond (KR) axion of the massless bosonic string gravitational multiplet. The latter may violate spontaneously CP and CPT symmetries, and induce leptogenesis during the radiation-dominated era in models involving right-handed neutrinos. The so-generated lepton asymmetry may then be communicated to the baryon sector by appropriate baryon-minus-lepton-number (B - L)-conserving, but (B + L)-violating, (sphaleron) processes in the Standard Model sector, thus leading to matter dominance over antimatter in the Universe.In the current (approximately de Sitter) era, the KR axion background may provide a source for an axionic dark matter in the Universe, through its mixing with other axions that are abundant in string models. As an interesting byproduct of our analysis, we demonstrate that the anomalies contribute to the vacuum energy density of the Universe terms of 'running-vacuum' type, proportional to the square of the Hubble parameter, $H^2$.

Sergei M. Kuzenko

For nonlinear models of an Abelian vector supermultiplet coupled to N = 2 supergravity in four dimensions, we formulate the self-duality equation which expresses invariance under U(1) duality rotations. In the flat space limit, this equation reduces to the N = 2 self-duality equation proposed in hep-th/0001068. We also give an example of a self-dual locally supersymmetric model containing a higher-derivative extension of the Born-Infeld action at the component level.

Nathan Berkovits, Joost Hoogeveen, Kostas Skenderis

This is the second of a series of two papers where decoupling of unphysical states in the minimal pure spinor formalism is investigated. The multi-loop amplitude prescription for the minimal pure spinor superstring formulated in hep-th/0406055 involves the insertion of picture changing operators in the path integral. In the first paper it was shown that these operators are not BRST closed inside correlators. Therefore a new proof of decoupling of BRST exact states is needed. In this paper we present such a proof, which applies to arbitrary genus. It relies in part on a (previously unnoticed) invariance of the path integral measure.

Alexander Quintero Vélez, A. Boer

In this paper we construct noncommutative resolutions of a certain class of Calabi-Yau threefolds studied by Cachazo et al. (Geometric transitions and N = 1 quiver theories. http://arxiv.org/abs/hep-th/0108120v2, 2001). The threefolds under consideration are fibered over a complex plane with the fibers being deformed Kleinian singularities. The construction is in terms of a noncommutative algebra introduced by Ginzburg (Calabi-Yau algebras. http://arxiv.org/abs/math/0612139v2, 2006) which we call the “N = 1 ADE quiver algebra”.

I. Y. Park

One-loop scattering on a stack of D3 branes was considered in arXiv:0801.0218 [hep-th]. Divergence was found and its cancelation mechanism was proposed, wherein it was conjectured that the D-brane geometry be introduced in the form of counter vertex operators. Here we verify the conjecture at the first few leading orders in an expansion method that we call large-$r_0$ expansion. We comment on the relation with the Fischler-Susskind mechanism and discuss the implications of our result for AdS/CFT.

G. Bonelli, A. Tanzini

We study cohomological gauge theories on total spaces of holomorphic line bundles over complex manifolds and obtain their reduction to the base manifold by U(1) equivariant localization of the path integral. We exemplify this general mechanism by proving via exact path integral localization a reduction for local curves conjectured in hep-th/0411280, relevant to the calculation of black hol e entropy/Gromov-Witten invariants. Agreement with the four-dimensional gauge theory is recovered by taking into account in the latter non-trivial contributions comin g from one-loop fluctuations determinants at the boundary of the total space. We also study a class of abelian gauge theories on Calabi-Yau local surfaces, describing the quantum foam for the A-model, relevant to the calculation of Donaldson-Thomas invariants.

Chunjian Zhang

D. Israel

In a recent paper (hep-th/0703157), Sen studied unstable D-branes in NS5-branes backgrounds and argued that in the strong curvature regime the universal open string tachyon (on D-branes of the wrong dimensionality) and the geometric tachyon (on D-branes that are BPS in flat space but not in this background) may become equivalent. We study in this note an example of a non-BPS suspended D-brane vs. a BPS D-brane at equal distance between two fivebranes. We use boundary worldsheet CFT methods to show that these two unstable branes are identical.

Fatih Erman, O. Turgut

In this work, we construct the nonrelativistic Lee model on some class of three dimensional Riemannian manifolds by following a novel approach introduced by S. G. Rajeev (e-print hep-th∕9902025). This approach together with the help of heat kernel allows us to perform the renormalization nonperturbatively and explicitly. For completeness, we show that the ground state energy is bounded from below for different classes of manifolds, using the upper bound estimates on the heat kernel. Finally, we apply a kind of mean field approximation to the model for compact and noncompact manifolds separately and discover that the ground state energy grows linearly with the number of bosons n.

J. Klusoň

This short note is devoted to the study of the Hamiltonian formalism and the integrability of the bosonic model introduced in [hep-th/0612079]. We calculate Poisson bracket of spatial components of Lax connection and we argue that its structure implies classical integrability of the theory.

M. Fukuma, H. Irie

We study (p, q) = (2, 4k) minimal superstrings within the minimal superstring field theory constructed in hep-th/0611045. We explicitly give a solution to the W1+∞ constraints by using charged D-instanton operators, and show that the (m, n)-instanton sector with m positive-charged and n negative-charged ZZ-branes is described by an (m + n) × (m + n) supermatrix model. We argue that the supermatrix model can be regarded as an open string field theory on the multi ZZ-brane system.

Federico Elmetti, Andrea Mauri, Marco Pirrone

We study the conformal invariance of non-planar beta-deformed N=4 SYM theory using the coupling constant reduction (CCR) formalism. We show that up to order g^10, differently from the planar case, we can remove the scheme dependence in the definition of the theory without reducing to the real beta case. We also compute the gauge beta function up to four loops and see that the generalized finiteness theorems proposed in [hep-th: 0705.1483] still hold.

R. Janik

In this talk I describe some applications of random matrix models to the study of N=1 supersymmetric Yang-Mills theories with matter fields in the fundamental representation. I review the derivation of the Veneziano-Yankielowicz-Taylor/Affleck-Dine-Seiberg superpotentials from constrained random matrix models (hep-th/0211082), a field theoretical justification of the logarithmic matter contribution to the Veneziano-Yankielowicz-Taylor superpotential (hep-th/0306242) and the random matrix based solution of the complete factorization problem of Seiberg-Witten curves for N=2 theories with fundamental matter (hep-th/0212212).

A. Lugo

Abstract We analyze in the spirit of hep-th/0110039 the possible existence of supersymmetric Dp– D p brane systems in flat ten-dimensional Minkowski space. For p=3,4 we show that besides the solutions related by T-duality to the D2– D 2 systems found by Bak and Karch there exist other ansatz whose compatibility is shown from general arguments and that preserve also eight supercharges, in particular, a D4– D 4 system with D2-branes dissolved on it and Taub–NUT charge. We carry out the explicit construction in Weyl basis of the corresponding Killing spinors and conjecture the existence of new solutions for higher-dimensional branes with some compact directions analogous to the supertube recently found.

O. Lisovyy

We derive determinant representations and nonlinear differential equations for the scaled 2-point functions of the 2D Ising model on the cylinder. These equations generalize well-known results for the infinite lattice (Painleve III equation and the equation for the τ -function of Painleve V). e-print archive: http://xxx.lanl.gov/hep-th/0108015

M. Bennai, E. Saidi

Abstract Using the algebraic geometry method of Berenstein and Leigh (BL) (hep-th/0009209 and hep-th/0105229), and considering singular toric varieties V d+1 with NC irrational torus fibration, we construct NC extensions M d nc of complex d dimension Calabi–Yau (CY) manifolds embedded in V d+1 nc . We give realizations of the NC C ∗r toric group, derive the constraint equations for NC Calabi–Yau (NCCY) manifolds M nc d embedded in V d+1 nc and work out solutions for their generators. We study fractional D branes at singularities and show that, due to the complete reducibility property of C ∗r group representations, there is an infinite number of noncompact fractional branes at fixed points of the NC toric group.

F. Finster

The Dirac sea is calculated in an expansion around the light cone. The method is to analyze the perturbation expansion for the Dirac sea in position space. This leads to integrals over expressions containing distributions which are singular on the light cone. We derive asymptotic formulas for these "light cone integrals" in terms of line integrals over the external potential and its partial derivatives. The calculations are based on the perturbation expansion for the Dirac sea in the preprint gr-qc/9606040 and yield the formulas listed in the appendix of this preprint. The results can be obtained easier with a combination of calculations in position and momentum space (see the corresponding preprints on the hep-th server). Therefore the calculations are preliminary and will remain unpublished; they are intended as reference for people who encounter similar mathematical problems.

B. Bakalov, E. Horozov, M. Yakimov

We announce a systematic way for constructing bispectral algebras of commuting differential operators of any rank N. It enables us to obtain all previously known classes and examples of bispectral operators. Moreover, we give a representation-theoretic explanation of the results including those of Duistermaat and Gr\"unbaum. The manifold of bispectral operators of any order is preserved by an hierarchy of symmetries. We point out that our methods provide a completely algorithmic procedure for obtaining bispectral algebras. We conjecture that the class built in the present paper exhausts all bispectral scalar operators. The proofs and details appeared in our preprints hep-th/9510211, q-alg/9602010, q-alg/9602011, q-alg/9602012.