INTERACTIONS AND SCATTERING IN d = 1 STRING THEORY

1991 ◽  
Vol 06 (16) ◽  
pp. 1465-1477 ◽  
Author(s):  
GAUTAM MANDAL ◽  
ANIRVAN M. SENGUPTA ◽  
SPENTA R. WADIA
Keyword(s):  
String Theory ◽  
Analytic Continuation ◽  
Time Of Flight ◽  
Density Fluctuations ◽  
Tree Level ◽  
Point Function

We discuss two results: (i) we calculate the two-point function of the density fluctuations to [Formula: see text] in the fermonic formulation of the d = 1 string theory and compare with the [Formula: see text] result from the candidate collective field Hamiltonian. The latter result is divergent, showing the inequivalence of the two theories. We find out the corrections to the collective field Hamiltonian (both in the form of infinite counterterms and additional finite pieces) needed to match with the fermion theory. (ii) We study tree-level scattering processes between bosons due to the localized interaction near the boundary (in a region of order [Formula: see text]). The reflection problem at the boundary is treated by an analytic continuation of the time-of-flight variable.

scholarly journals Loops in AdS: from the spectral representation to position space. Part II

2021 ◽  
Vol 2021 (7) ◽  
Author(s):  
Dean Carmi
Keyword(s):  
Spectral Representation ◽  
Tree Level ◽  
Point Function ◽  
Position Space ◽  
Gross Neveu Model ◽  
Loop Amplitudes

Abstract We continue the study of AdS loop amplitudes in the spectral representation and in position space. We compute the finite coupling 4-point function in position space for the large-N conformal Gross Neveu model on AdS3. The resummation of loop bubble diagrams gives a result proportional to a tree-level contact diagram. We show that certain families of fermionic Witten diagrams can be easily computed from their companion scalar diagrams. Thus, many of the results and identities of [1] are extended to the case of external fermions. We derive a spectral representation for ladder diagrams in AdS. Finally, we compute various bulk 2-point correlators, extending the results of [1].

scholarly journals STRING COSMOLOGY AND CHAOS

2004 ◽  
Vol 19 (10) ◽  
pp. 1499-1509
Author(s):  
THIBAULT DAMOUR
Keyword(s):  
String Theory ◽  
Coming Out ◽  
String Cosmology ◽  
Low Energy ◽  
Weyl Groups ◽  
Tree Level ◽  
Cosmological Solutions

We briefly review two aspects of string cosmology: (1) the presence of chaos in the generic cosmological solutions of the tree-level low-energy effective actions coming out of string theory, and (2) the remarkable link between the latter chaos and the Weyl groups of some hyperbolic Kac–Moody algebras.

scholarly journals ZERO MODE DIVERGENCE PROBLEM IN STRING THEORY

1994 ◽  
Vol 09 (23) ◽  
pp. 2113-2122
Author(s):  
MAKOTO NATSUUME
Keyword(s):  
String Theory ◽  
Zero Mode ◽  
Wave Packets ◽  
Tree Level ◽  
Formal Schemes ◽  
Divergence Problem ◽  
Formal Procedures

For 2D string theory, the perturbative S-matrices are not well-defined due to a zero mode divergence. Although there exist formal procedures to make the integral convergent, their physical meanings are not clear. We describe a method to obtain finite S-matrices physically to justify the formal schemes. The scheme uses asymptotic states by wave packets which fall faster than exponentials. It is shown that the scheme gives well-defined S-matrices and justifies the formal shifted Virasoro-Shapiro amplitude for simple processes. The tree-level unitarity for these processes is also shown. We point out a problem in this scheme.

scholarly journals OPEN-CLOSED DUALITY: LESSONS FROM MATRIX MODEL

2004 ◽  
Vol 19 (11) ◽  
pp. 841-853 ◽  
Author(s):  
ASHOKE SEN
Keyword(s):  
Field Theory ◽  
String Theory ◽  
Matrix Model ◽  
String Field Theory ◽  
Classical Result ◽  
Open String ◽  
Closed String ◽  
Tree Level ◽  
Two Dimensional

Recent investigations involving the decay of unstable D-branes in string theory suggest that the tree level open string theory which describes the dynamics of the D-brane already knows about the closed string states produced in the decay of the brane. We propose a specific conjecture involving quantum open string field theory to explain this classical result, and show that the recent results in two-dimensional string theory are in exact accordance with this conjecture.

scholarly journals The inflationary wavefunction from analyticity and factorization

2021 ◽  
Vol 2021 (12) ◽  
pp. 018
Author(s):  
David Meltzer
Keyword(s):  
Analytic Continuation ◽  
De Sitter Space ◽  
Conformal Group ◽  
Tree Level ◽  
Late Time ◽  
De Sitter ◽  
Scale Invariant ◽  
Arbitrary Mass ◽  
Lower Point ◽  
Finite Sum

Abstract We study the analytic properties of tree-level wavefunction coefficients in quasi-de Sitter space. We focus on theories which spontaneously break dS boost symmetries and can produce significant non-Gaussianities. The corresponding inflationary correlators are (approximately) scale invariant, but are not invariant under the full conformal group. We derive cutting rules and dispersion formulas for the late-time wavefunction coefficients by using factorization and analyticity properties of the dS bulk-to-bulk propagator. This gives a unitarity method which is valid at tree-level for general n-point functions and for fields of arbitrary mass. Using the cutting rules and dispersion formulas, we are able to compute n-point functions by gluing together lower-point functions. As an application, we study general four-point, scalar exchange diagrams in the EFT of inflation. We show that exchange diagrams constructed from boost-breaking interactions can be written as a finite sum over residues. Finally, we explain how the dS identities used in this work are related by analytic continuation to analogous identities in Anti-de Sitter space.

scholarly journals SOME REMARKS ON TACHYON ACTION IN 2D STRING THEORY

1993 ◽  
Vol 08 (26) ◽  
pp. 2481-2489 ◽  
Author(s):  
MIAO LI
Keyword(s):  
String Theory ◽  
Effective Action ◽  
Tree Level ◽  
Two Dimensional

We discuss the effective action of tachyon in the two-dimensional string theory at tree level. We show that even starting from the cubic terms the action is nonlocal and the usually assumed simplest cubic term does not give the correct amplitude. Four-point 1PI terms are also discussed.

scholarly journals Tree-level stability without spacetime fermions: novel examples in string theory

2007 ◽  
Vol 2007 (07) ◽  
pp. 065-065 ◽  
Author(s):  
Dan Israël ◽  
Vasilis Niarchos
Keyword(s):  
String Theory ◽  
Tree Level
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