Related papers: 2D String Theory Coupled to Quantum Gravity
We develop a method for computing the linearized gravitational backreaction for Nambu-Goto strings using a fully covariant formalism. We work with equations of motion expressed in terms of a higher dimensional analog of the geodesic…
Two-dimensional quantum gravity with an $R^2$ term is investigated in the continuum framework. It is shown that the partition function for small area $A$ is highly suppressed by an exponential factor $exp \{ -2\pi (1-h)^2/(m^2A) \}$, where…
Quantization of 4-dimensional Nambu-Goto theory of open string in light cone gauge, related in Lorentz-invariant way with the world sheet, is performed. Obtained quantum theory has no anomalies in Lorentz group. Determined spin-mass spectra…
The concept of the quantized space-time of the formless finite fundamental elements is suggested. This space-time can be defined as a set of continual space-time coverings by simply connected non-overlapping regions of any form and…
We propose a modification of the Nambu-Goto action for the bosonic string which is compatible with the existence of a minimum area at the Planck scale. The result is a phenomenological action based on the observation that LQG tells us that…
I consider a three-dimensional string theory whose action, besides the standard area term, contains one of the form $\int_{\Sigma} \epsilon_{\mu\nu\sigma} X^{\mu} d X^{\nu} \wedge d X^{\sigma}$. In the case of closed strings this extra term…
In this paper, which is a revised version of the author's PhD thesis, we analyze two different applications of string theory. In the first part, we focus on four dimensional compactifications of Type II string theories preserving N=1…
We show that the measure of the three dimensional Nambu-Goto string theory has a simple decomposition as a measure on two parameter group of induced area-preserving transformations of the immersed surface and a trivial measure for the area…
Two kinds of statistical properties of dynamical-triangulated manifolds (DT mfds) have been investigated. First, the surfaces appearing on the boundaries of 3D DT mfds were investigated. The string-susceptibility exponent of the boundary…
The equation of motion for comohogeneity-one Nambu-Goto strings in flat space $\mathbb{R}^{n,1}$ has been investigated. We first classify possible forms of the Killing vector fields in $\mathbb{R}^{n,1}$ after appropriate action of the…
We compute semi-classical corrections to the energy of rotating open Nambu-Goto strings with and without masses at the ends, using methods from quantum field theory on curved space-times.
The effective action on long strings, such as confining strings in pure Yang-Mills theories, is well-approximated by the Nambu-Goto action, but this action cannot be exact. The leading possible corrections to this action (in a long string…
General solutions of a gravitational junction between two copies of a three-dimensional Einstein manifold $\mathcal{M}$ correspond to the solutions of the non-linear Nambu-Goto equation for a string in $\mathcal{M}$. We show that, for the…
We explore the formation of cosmic string Y-junctions when strings of two different types collide, which has recently become important since string theory can yield cosmic strings of distinct types. Using a model containing two types of…
I discuss the recent progress in bypassing the KPZ barrier for the existence of nonperturbative bosonic strings in $1<d<25$. I consider string anomalies which emerge from higher terms of the DeWitt-Seeley expansion as $\varepsilon \times…
The partition function of two dimensional QCD on a Riemann surface of area $A$ is expanded as a power series in $1/N$ and $A$. It is shown that the coefficients of this expansion are precisely determined by a sum over maps from a two…
We investigate stationary rotating closed Nambu-Goto strings in five-dimensional flat spacetime. The stationary string is defined as a worldsheet that is tangent to a timelike Killing vector. Nambu-Goto equation of motion for the stationary…
We consider the effects of going beyond the approximation of a straight string in mesons by using a flexible flux tube model wherein a Nambu-Goto string bends in response to quark accelerations. The curved string is dynamically identical to…
The classical linearised gravitational self interaction of a Goto-Nambu string is examined in four spacetime dimensions. Using a conveniently gauge independent tensorial treatment, the divergent part of the self-force is shown to be exactly…
We assume the bosonic string is a composite object of the relativistic particles. The behavior of the relativistic particles in a curve enables us to obtain the Nambu-Goto and the Polyakov actions of the bosonic string. We observe that the…