Suresh Govindarajan

Bio: Suresh Govindarajan is an academic researcher from Indian Institute of Technology Madras. The author has contributed to research in topics: Superpotential & Siegel modular form. The author has an hindex of 21, co-authored 130 publications receiving 1500 citations. Previous affiliations of Suresh Govindarajan include University of Pennsylvania & Indian Institutes of Technology.

Chiral Rings and Physical States in c<1 String Theory

Abstract: We show how the double cohomology of the String and Felder BRST charges naturally leads to the ring structure of $c<1$ strings. The chiral ring is a ring of polynomials in two variables modulo an equivalence relation of the form $x^p \simeq y^{p+1}$ for the (p+1,p) model. We also study the states corresponding to the edges of the conformal grid whose inclusion is crucial for the closure of the ring. We introduce candidate operators that correspond to the observables of the matrix models. Their existence is motivated by the relation of one of the screening operators of the minimal model to the zero momentum dilaton.

Numerical analysis on the applicability of sorption isotherm models in aquifers and its correlation with recharged water movement

Abstract: Sorption is a necessary process influencing the subsurface solute or contaminant transport. There are many adsorption isotherms, and selecting one to represent the system is likely to remain an elusive goal. Also, the lack of observed data and its associated certainty may hinder the determination of sorption parameters. This study investigated the influence of different isotherms – linear adsorption assumption, Freundlich isotherm, Langmuir isotherm, and Redlich – Peterson isotherm, on chloride concentrations. The numerical model also gauged the extent of recharged waters migrating from the injection well. Temporal analysis of groundwater resident volumes helped to understand better the change in chloride concentrations with the selected isotherm. The residual solute concentrations from the isotherms followed the order: Redlich – Peterson < Freundlich < Langmuir. The results highlighted the importance of obtaining a range of sorption values rather than a single value from one fitted isotherm for the productive aid in groundwater decision making.

On Physical States in c<1 String Theory

Abstract: The BRST cohomology analysis of Lian and Zuckerman leads to physical states at all ghost number for $c<1$ matter coupled to Liouville gravity. We show how these states are related to states at ghost numbers zero(pure vertex operator states -- DK states) and ghost number one(ring elements) by means of descent equations. These descent equations follow from the double cohomology of the String BRST and Felder BRST operators. We briefly discuss how the ring elements allow one to determine all correlation functions on the sphere.

Comparison of supercritical co 2 1 with water as geofluid in 2 geothermal reservoirs with 3 numerical investigation using fully 4 coupled thermo-hydro- 5 geomechanical model

Abstract: 48 In the present work, fully coupled dynamic thermo-hydro-mechanical (THM) model was employed to 49 investigate the advantage and disadvantages of supercritical CO 2 (SCCO 2 ) over water as geofluids. Low- 50 temperature zone was found in both SCCO 2 -EGS and water-EGS systems, but spatial expansion is higher in 51 water-EGS. Although, the spatial expansion of SCCO 2 into the rock matrix will help in the geo-sequestration. 52 The expansion of stress and strain invaded zones were identified significantly in the vicinity of fracture and 53 injection well. SCCO 2 -EGS system is giving better thermal breakthrough and geothermal life conditions 54 compared to the water-EGS system. Reservoir flow impedance (RFI) and heat power are examined, and heat 55 power are high in the water-EGS system. Minimum RFI is found in the SCCO 2 -EGS system at 45 C  and 0.05 56 m/s. Maximum heat power for SCCO 2 -EGS was observed at 35 C  , 20 MPa, and 0.15 m/s. Therefore, the 57 developed dynamic THM model is having greater abilities to examine behaviour of SCCO 2 -EGS and water- 58 EGS systems effectively. The variations occur in the rock matrix and the performance indicators are 59 dependent on the type of fluid, injection/production velocities, initial reservoir pressure, injection 60 temperature. The advantages of SCCO 2 -EGS system over the water-EGS system, providing a promising result 61 to the geothermal industry as geofluid.

The Topological Vertex

Abstract: We construct a cubic field theory which provides all genus amplitudes of the topological A-model for all non-compact toric Calabi-Yau threefolds. The topology of a given Feynman diagram encodes the topology of a fixed Calabi-Yau, with Schwinger parameters playing the role of Kahler classes of the threefold. We interpret this result as an operatorial computation of the amplitudes in the B-model mirror which is the quantum Kodaira-Spencer theory. The only degree of freedom of this theory is an unconventional chiral scalar on a Riemann surface. In this setup we identify the B-branes on the mirror Riemann surface as fermions related to the chiral boson by bosonization.

Moduli spaces of local systems and higher Teichmüller theory

Abstract: Let G be a split semisimple algebraic group over Q with trivial center. Let S be a compact oriented surface, with or without boundary. We define positive representations of the fundamental group of S to G(R), construct explicitly all positive representations, and prove that they are faithful, discrete, and positive hyperbolic; the moduli space of positive representations is a topologically trivial open domain in the space of all representations. When S have holes, we defined two moduli spaces closely related to the moduli spaces of G-local systems on S. We show that they carry a lot of interesting structures. In particular we define a distinguished collection of coordinate systems, equivariant under the action of the mapping class group of S. We prove that their transition functions are subtraction free. Thus we have positive structures on these moduli spaces. Therefore we can take their points with values in any positive semifield. Their positive real points provide the two higher Teichmuller spaces related to G and S, while the points with values in the tropical semifields provide the lamination spaces. We define the motivic avatar of the Weil–Petersson form for one of these spaces. It is related to the motivic dilogarithm.

The statistics of string/M theory vacua

Abstract: We discuss systematic approaches to the classification of string/M theory vacua, and physical questions this might help us resolve. To this end, we initiate the study of ensembles of effective Lagrangians, which can be used to precisely study the predictive power of string theory, and in simple examples can lead to universality results. Using these ideas, we outline an approach to estimating the number of vacua of string/M theory which can realize the Standard Model.