scholarly journals BRANE SOLUTIONS IN TIME-DEPENDENT BACKGROUNDS IN D = 11 SUPERGRAVITY AND IN TYPE II STRING THEORIES

2008 ◽  
Vol 23 (16n17) ◽  
pp. 2525-2540 ◽  
Author(s):  
SRIKUMAR SEN GUPTA
Keyword(s):  
String Theory ◽  
Equations Of Motion ◽  
Space Time ◽  
Time Dependent ◽  
Type Ii ◽  
Reduced Equations ◽  
Special Cases ◽  
M Theory ◽  
String Theories

We obtain explicit time-dependent brane solutions in M-theory as well as in string theory by solving the reduced equations of motion (which follow, as in Int. J. Mod. Phys. A17, 4647 (2002), from 11-dimensional supergravity) for a class of brane solutions in curved backgrounds. The behavior of our solutions in both asymptotic and near-horizon limits are studied. It is shown that our time-dependent solutions serve as explicit examples of branes in singular, cosmological backgrounds. In some special cases the asymptotic and the boundary AdS solutions can be identified as Milne × Rn space–time.

scholarly journals Implication of U-duality for black branes in string/M-theory

2016 ◽  
Vol 31 (01) ◽  
pp. 1650001
Author(s):  
Samrat Bhowmick
Keyword(s):  
String Theory ◽  
Explicit Form ◽  
Energy Momentum Tensor ◽  
Momentum Tensor ◽  
Time Dependent ◽  
Type Ii ◽  
Black Brane ◽  
Duality Symmetry ◽  
M Theory ◽  
Time Dependent System

U-duality symmetry of M-theory and S- and T-duality of string theory can be used to study various black brane solutions. We explore some aspect of this idea here. This symmetry can be used to get relations among various components of the metric of the black brane. These relations in turn give relations among various components of the energy–momentum tensor. We show that, using these relations, without knowing the explicit form of form fields, we can get the black brane solutions. These features were studied previously in the context of M-theory. Here, we extensively studied them in string theory (type II supergravity). We also show that this formulation works for exotic branes. We give an example of a time-dependent system where this method is essential.

scholarly journals GENERALIZED W3-STRINGS FROM FREE FIELDS

1995 ◽  
Vol 10 (06) ◽  
pp. 515-524 ◽  
Author(s):  
J. M. FIGUEROA-O'FARRILL ◽  
C. M. HULL ◽  
L. PALACIOS ◽  
E. RAMOS
Keyword(s):  
Bosonic Strings ◽  
Free Field ◽  
Space Time ◽  
General Construction ◽  
Special Cases ◽  
Free Fields ◽  
Rule Out ◽  
General Conditions ◽  
String Theories

The conventional quantization of w3-strings gives theories which are equivalent to special cases of bosonic strings. We explore whether a more general quantization can lead to new generalized W3-string theories by seeking to construct quantum BRST charges directly without requiring the existence of a quantum W3-algebra. We study W3-like strings with a direct space-time interpretation — that is, with matter given by explicit free field realizations. Special emphasis is placed on the attempt to construct a quantum W-string associated with the magic realizations of the classical w3-algebra. We give the general conditions for the existence of W3-like strings, and comment on how the known results fit into our general construction. Our results are negative: we find no new consistent string theories, and in particular rule out the possibility of critical strings based on the magic realizations.

ON THE INTERPOLATING SOLUTIONS OF STRING IN DIFFERENT BACKGROUNDS

1992 ◽  
Vol 07 (15) ◽  
pp. 1361-1366 ◽  
Author(s):  
SUDIPTA MUKHERJI
Keyword(s):  
Field Theory ◽  
Conformal Field Theory ◽  
String Theory ◽  
Central Charge ◽  
Space Time ◽  
Time Dependent ◽  
Target Space ◽  
Conformal Field ◽  
Β Function ◽  
Time Dependent Solution

We analyze the β-function equations for string theory in the case when the target space has one space-like (or time-like) direction and the rest is some conformal field theory (CFT) with appropriate central charge and has one nearly marginal operator. We show there always exists a space-(time) dependent solution which interpolates between the original background and the background where CFT is replaced by a new conformal field theory, obtained by perturbing CPT by the nearly marginal operator.

CHIRAL (SUPER) STRING ACTIONS

1990 ◽  
Vol 05 (07) ◽  
pp. 1341-1361 ◽  
Author(s):  
S.M. KUZENKO ◽  
O.A. SOLOVIEV
Keyword(s):  
String Theory ◽  
Space Time ◽  
Heterotic String ◽  
Bosonic String ◽  
Dimensional Case ◽  
Anomaly Cancellation ◽  
Heterotic String Theory ◽  
Covariant Action ◽  
Heterotic String Theories ◽  
String Theories

We present a covariant action describing chiral bosonic string theories in space-time dimensions d<26 and a covariant (1, 0) supersymmetric action describing heterotic string theories in space-time of dimension d<10. The anomaly cancellation conditions are found. In the four-dimensional case the supersymmetric action corresponds to the SO(44) heterotic string theory.

scholarly journals DUALITY IN EQUATIONS OF MOTION FROM SPACE–TIME DEPENDENT LAGRANGIANS

2000 ◽  
Vol 15 (14) ◽  
pp. 901-911 ◽  
Author(s):  
RAJSEKHAR BHATTACHARYYA ◽  
DEBASHIS GANGOPADHYAY
Keyword(s):  
Equations Of Motion ◽  
Space Time ◽  
Quantization Condition ◽  
Time Dependent ◽  
Classical Solutions ◽  
String Solution ◽  
Yang Mills ◽  
Dirac Quantization ◽  
Lagrangian Field Theory ◽  
Condition C

Starting from Lagrangian field theory and the variational principle, we show that duality in equations of motion can also be obtained by introducing explicit space–time dependence of the Lagrangian. Poincaré invariance is achieved precisely when the duality conditions are satisfied in a particular way. The same analysis and criteria are valid for both Abelian and non-Abelian dualities. We illustrate how (a) Dirac string solution, (b) Dirac quantization condition, (c) 't Hooft–Polyakov monopole solutions and (d) a procedure emerges for obtaining new classical solutions of Yang–Mills (YM) theory. Moreover, these results occur in a way that is strongly reminiscent of the holographic principle.

scholarly journals SCHRÖDINGER EQUATIONS WITH TIME-DEPENDENT P2 AND X2 TERMS

2002 ◽  
Vol 17 (11) ◽  
pp. 1559-1575
Author(s):  
MICHAEL MARTIN NIETO ◽  
D. RODNEY TRUAX
Keyword(s):  
Continuous Function ◽  
Lie Algebra ◽  
Coherent States ◽  
Schrodinger Equation ◽  
Space Time ◽  
Time Dependent ◽  
Squeezed States ◽  
Special Cases ◽  
Dependent Mass ◽  
Schrödinger System

We present some general results for the time-dependent mass Hamiltonian problem with H=-½e-2ν(t)∂xx+h(2)(t)e2ν(t)x2, where ν(t) is a continuous function of t. This Hamiltonian corresponds to a time-dependent mass (TM) Schrödinger equation with the restriction that there are only P2 and X2 terms. We give the specific transformations to a different quadratic Schrödinger (TQ) equation and to a different time-dependent oscillator (TO) equation. For each Schrödinger system, we give the Lie algebra of space–time symmetries and (x,t) representations for number states, coherent states and squeezed states. These general results include earlier works as special cases.

scholarly journals ON EFFECTIVE F-THEORY ACTION IN TYPE IIA COMPACTIFICATIONS

2007 ◽  
Vol 22 (07) ◽  
pp. 1279-1300 ◽  
Author(s):  
IGOR KRIZ ◽  
HAO XING
Keyword(s):  
String Theory ◽  
Partition Function ◽  
Effective Action ◽  
Space Time ◽  
Elliptic Cohomology ◽  
Pontrjagin Class ◽  
Geometric Term ◽  
M Theory ◽  
Special Case

Diaconescu, Moore and Witten proved that the partition function of type IIA string theory coincides (to the extent checked) with the partition function of M-theory. One of us (Kriz) and Sati proposed in a previous paper a refinement of the IIA partition function using elliptic cohomology and conjectured that it coincides with a partition function coming from F-theory. In this paper, we define the geometric term of the F-theoretical effective action on type IIA compactifications. In the special case when the first Pontrjagin class of space–time vanishes, we also prove a version of the Kriz–Sati conjecture by extending the arguments of Diaconescu–Moore–Witten. We also briefly discuss why even this special case allows interesting examples.

scholarly journals ON FAIRLIE'S MOYAL FORMULATION OF M(ATRIX)-THEORY

2001 ◽  
Vol 16 (31) ◽  
pp. 4969-4984
Author(s):  
M. HSSAINI ◽  
M. B. SEDRA ◽  
M. BENNAI ◽  
B. MAROUFI
Keyword(s):  
Poisson Bracket ◽  
Explicit Form ◽  
Simple Form ◽  
Equations Of Motion ◽  
Yang Mills ◽  
First Order ◽  
Large N ◽  
Special Cases ◽  
M Theory ◽  
Conserved Currents

Starting from the Moyal formulation of M theory in the large N-limit, we propose to reexamine the associated membrane equations of motion in ten dimensions formulated in terms of Poisson bracket. Among the results obtained, we rewrite the coupled first order Nahm equations into a simple form leading in turn to their systematic relation with SU (∞) Yang–Mills equations of motion. The former are interpreted as the vanishing condition of some conserved currents which we propose. We develop also an algebraic analysis in which an ansatz is considered and find an explicit form for the membrane solution of our problem. Typical solutions known in literature can also emerge as special cases of the proposed solution.

scholarly journals ON THE BEKENSTEIN–HAWKING ENTROPY, NONCOMMUTATIVE BRANES AND LOGARITHMIC CORRECTIONS

2006 ◽  
Vol 21 (22) ◽  
pp. 4449-4461 ◽  
Author(s):  
AXEL KRAUSE
Keyword(s):  
String Theory ◽  
Event Horizon ◽  
Dimensional Space ◽  
Logarithmic Correction ◽  
Type Ii ◽  
Logarithmic Corrections ◽  
Higher Dimensional ◽  
M Theory ◽  
Microscopic Origin

We extend our earlier work on the possible microscopic origin of the Bekenstein–Hawking entropy to higher-dimensional space–times. The mechanism of counting chain-like states is shown to work for space–times with event horizon wrapped by a Euclidean doublet (E1,M1)+(E2,M2) of electric–magnetic dual brane pairs of type II string-theory or M-theory. Noncommutativity on the brane worldvolume enters naturally the derivation of the Bekenstein–Hawking entropy including the correct prefactor. Moreover, a logarithmic correction with prefactor 1/2 is predicted.

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