scholarly journals ON LOOP EQUATIONS IN KdV EXACTLY SOLVABLE STRING THEORY

1992 ◽  
Vol 07 (14) ◽  
pp. 1263-1272 ◽  
Author(s):  
SIMON DALLEY
Keyword(s):  
String Theory ◽  
Cosmological Constant ◽  
The Other ◽  
Half Line ◽  
String Equation ◽  
Minimal Models ◽  
The Real ◽  
Exactly Solvable ◽  
Scale Transformations ◽  
String Theories

The non-perturbative behavior of macroscopic loop amplitudes in the exactly solvable string theories based on the KdV hierarchies is considered. Loop equations are presented for the real non-perturbative solutions living on the spectral half-line, allowed by the most general string equation [Formula: see text], where [Formula: see text] generates scale transformations. In general the end of the half-line (the 'wall') is a non-perturbative parameter whose role is that of boundary cosmological constant. The properties are compared with the perturbative behavior and solutions of [P, Q]=1. Detailed arguments are given for the (2,2m-1) models while generalization to the other (p,q) minimal models and c=1 is briefly addressed.

scholarly journals QUANTIZING HIGHER-SPIN STRING THEORIES

1995 ◽  
Vol 10 (14) ◽  
pp. 2123-2142 ◽  
Author(s):  
H. LU ◽  
X.J. WANG ◽  
K.-W. XU ◽  
C.N. POPE ◽  
K. THIELEMANS
Keyword(s):  
String Theory ◽  
Classical Theory ◽  
Energy Momentum Tensor ◽  
Standard Form ◽  
Momentum Tensor ◽  
Minimal Models ◽  
Classical Level ◽  
Higher Spin ◽  
String Theories ◽  
The Way

In this paper, we examine the conditions under which a higher-spin string theory can be quantized. The quantizability is crucially dependent on the way in which the matter currents are realized at the classical level. In particular, we construct classical realizations for the W2,s algebra, which is generated by a primary spin-s current in addition to the energy-momentum tensor, and discuss the quantization for s≤8. From these examples we see that quantum BRST operators can exist even when there is no quantum generalization of the classical W2,s algebra. Moreover, we find that there can be several inequivalent ways of quantizing a given classical theory, leading to different BRST operators with inequivalent cohomologies. We discuss their relation to certain minimal models. We also consider the hierarchical embeddings of string theories proposed recently by Berkovits and Vafa, and show how the already known W strings provide examples of this phenomenon. Attempts to find higher-spin fermionic generalizations lead us to examine whether classical BRST operators for [Formula: see text](n odd) algebras can exist. We find that even though such fermionic algebras close up to null fields, one cannot build nilpotent BRST operators, at least of the standard form.

scholarly journals ON HIGHER-SPIN GENERALIZATIONS OF STRING THEORY

1994 ◽  
Vol 09 (09) ◽  
pp. 1527-1543 ◽  
Author(s):  
H. LU ◽  
C. N. POPE ◽  
X. J. WANG
Keyword(s):  
String Theory ◽  
Gauge Field ◽  
Virasoro Algebra ◽  
Two Dimensional ◽  
Minimal Models ◽  
World Sheet ◽  
The World ◽  
Higher Spin ◽  
String Theories

We construct BRST operators for certain higher-spin extensions of the Virasoro algebra, in which there is a spin-s gauge field on the world sheet, as well as the spin-2 gauge field corrresponding to the two-dimensional metric. We use these BRST operators to study the physical states of the associated string theories, and show how they are related to certain minimal models.

scholarly journals PERTURBING THE GROUND RING OF 2D STRING THEORY

1992 ◽  
Vol 07 (30) ◽  
pp. 7579-7595 ◽  
Author(s):  
J.L.F. BARBÓN
Keyword(s):  
String Theory ◽  
Cosmological Constant ◽  
Matrix Model ◽  
Current Algebra ◽  
Free Field ◽  
Three Dimensional ◽  
Ring Structure ◽  
Geometrical Interpretation ◽  
The Other ◽  
Field Techniques

We use free field techniques in D=2 string theory to calculate the perturbation of the special state algebras when the cosmological constant is turned on. In particular, we find that the “ground cone” preserved by the ring structure is promoted to a three-dimensional hyperboloid as conjectured by Witten. On the other hand, the perturbed (1, 1) current algebra of moduli deformations is computed completely, and no simple geometrical interpretation is found. We also quote some facts concerning the Liouville matrix model dictionary in this class of theories.

Hidden “holes” in the capital of banks and the supply of credit to the real sector of economy

2018 ◽  
pp. 49-68 ◽  
Author(s):  
M. E. Mamonov
Keyword(s):  
Credit Risk ◽  
The Other ◽  
Real Sector ◽  
Capital Management ◽  
Loan Loss ◽  
Short Term ◽  
The Real ◽  
Ex Post ◽  
The One

Our analysis documents that the existence of hidden “holes” in the capital of not yet failed banks - while creating intertemporal pressure on the actual level of capital - leads to changing of maturity of loans supplied rather than to contracting of their volume. Long-term loans decrease, whereas short-term loans rise - and, what is most remarkably, by approximately the same amounts. Standardly, the higher the maturity of loans the higher the credit risk and, thus, the more loan loss reserves (LLP) banks are forced to create, increasing the pressure on capital. Banks that already hide “holes” in the capital, but have not yet faced with license withdrawal, must possess strong incentives to shorten the maturity of supplied loans. On the one hand, it raises the turnovers of LLP and facilitates the flexibility of capital management; on the other hand, it allows increasing the speed of shifting of attracted deposits to loans to related parties in domestic or foreign jurisdictions. This enlarges the potential size of ex post revealed “hole” in the capital and, therefore, allows us to assume that not every loan might be viewed as a good for the economy: excessive short-term and insufficient long-term loans can produce the source for future losses.

scholarly journals ON p – q DUALITY AND EXPLICIT SOLUTIONS IN c ≤ 1 2D GRAVITY MODELS

1995 ◽  
Vol 10 (08) ◽  
pp. 1219-1236 ◽  
Author(s):  
S. KHARCHEV ◽  
A. MARSHAKOV
Keyword(s):  
String Theory ◽  
Exact Solutions ◽  
2D Gravity ◽  
Integral Formula ◽  
Integral Representations ◽  
Gravity Models ◽  
Explicit Solutions ◽  
String Equation ◽  
Duality Transformation

We study the role of integral representations in the description of nonperturbative solutions to c ≤ 1 string theory. A generic solution is determined by two functions, W(x) and Q(x), which behave at infinity like xp and xq respectively. The integral formula for arbitrary (p, q) models is derived, which explicitly realizes a duality transformation between (p, q) and (q, p) 2D gravity solutions. We also discuss the exact solutions to the string equation and reduction condition and present several explicit examples.

scholarly journals Standard model from a supergravity model with a naturally small cosmological constant

2021 ◽  
Vol 2021 (5) ◽  
Author(s):  
Shing Yan Li ◽  
Yu-Cheng Qiu ◽  
S.-H. Henry Tye
Keyword(s):  
String Theory ◽  
Standard Model ◽  
Cosmological Constant ◽  
Supersymmetry Breaking ◽  
Supersymmetric Standard Model ◽  
Degrees Of Freedom ◽  
Interaction Terms ◽  
Supersymmetric Version ◽  
The Standard Model ◽  
Linear Version

Abstract Guided by the naturalness criterion for an exponentially small cosmological constant, we present a string theory motivated 4-dimensional $$ \mathcal{N} $$ N = 1 non-linear supergravity model (or its linear version with a nilpotent superfield) with spontaneous supersymmetry breaking. The model encompasses the minimal supersymmetric standard model, the racetrack Kähler uplift, and the KKLT anti-D3-branes, and use the nilpotent superfield to project out the undesirable interaction terms as well as the unwanted degrees of freedom to end up with the standard model (not the supersymmetric version) of strong and electroweak interactions.

scholarly journals On supersymmetric AdS4 orientifold vacua

2020 ◽  
Vol 2020 (8) ◽  
Author(s):  
Fernando Marchesano ◽  
Eran Palti ◽  
Joan Quirant ◽  
Alessandro Tomasiello
Keyword(s):  
String Theory ◽  
Cosmological Constant ◽  
Bianchi Identities ◽  
Expansion Parameter ◽  
First Order ◽  
Ricci Flat ◽  
Key Features ◽  
One To One ◽  
Calabi Yau Manifolds

Abstract In this work we study ten-dimensional solutions to type IIA string theory of the form AdS4 × X6 which contain orientifold planes and preserve $$ \mathcal{N} $$ N = 1 supersymmetry. In particular, we consider solutions which exhibit some key features of the four-dimensional DGKT proposal for compactifications on Calabi-Yau manifolds with fluxes, and in this sense may be considered their ten-dimensional uplifts. We focus on the supersymmetry equations and Bianchi identities, and find solutions to these that are valid at the two-derivative level and at first order in an expansion parameter which is related to the AdS cosmological constant. This family of solutions is such that the background metric is deformed from the Ricci-flat one to one exhibiting SU(3) × SU(3)-structure, and dilaton gradients and warp factors are induced.

scholarly journals de Sitter in non-supersymmetric string theories: no-go theorems and brane-worlds

2020 ◽  
Vol 2020 (10) ◽  
Author(s):  
Ivano Basile ◽  
Stefano Lanza
Keyword(s):  
Flux Compactifications ◽  
Cosmological Constant ◽  
Dimensional Reduction ◽  
Brane World ◽  
De Sitter ◽  
Top Down ◽  
Brane Worlds ◽  
Concrete Realization ◽  
String Models ◽  
String Theories

Abstract We study de Sitter configurations in ten-dimensional string models where supersymmetry is either absent or broken at the string scale. To this end, we derive expressions for the cosmological constant in general warped flux compactifications with localized sources, which yield no-go theorems that extend previous works on supersymmetric cases. We frame our results within a dimensional reduction and connect them to a number of Swampland conjectures, corroborating them further in the absence of supersymmetry. Furthermore, we construct a top-down string embedding of de Sitter brane-world cosmologies within unstable anti-de Sitter landscapes, providing a concrete realization of a recently revisited proposal.

scholarly journals META-STABLE BRANE CONFIGURATIONS WITH MULTIPLE NS5-BRANES

2009 ◽  
Vol 24 (27) ◽  
pp. 5051-5120
Author(s):  
CHANGHYUN AHN
Keyword(s):  
Gauge Theory ◽  
String Theory ◽  
Gauge Group ◽  
Gauge Theories ◽  
The Other ◽  
Multiple Product

Starting from an [Formula: see text] supersymmetric electric gauge theory with the multiple product gauge group and the bifundamentals, we apply Seiberg dual to each gauge group, obtain the [Formula: see text] supersymmetric dual magnetic gauge theories with dual matters including the gauge singlets. Then we describe the intersecting brane configurations, where there are NS-branes and D4-branes (and anti-D4-branes), of type IIA string theory corresponding to the meta-stable nonsupersymmetric vacua of this gauge theory. We also discuss the case where the orientifold 4-planes are added into the above brane configuration. Next, by adding an orientifold 6-plane, we apply to an [Formula: see text] supersymmetric electric gauge theory with the multiple product gauge group (where a single symplectic or orthogonal gauge group is present) and the bifundamentals. Finally, we describe the other cases where the orientifold 6-plane intersects with NS-brane.

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