31 citations · 69 across the 13 of their papers we have counts for
14 papers
CMB Injection Bounds on Moduli Fields
Naman Agarwal, Andrew R. Frey, Ratul Mahanta +3
Light scalar fields with gravitational strength interactions (moduli) are ubiquitous in string, supergravity, and extra-dimensional models. If produced in the early universe with l…
Quadratic Axion Couplings in String Theory
Naman Agarwal, Andrew R. Frey, Ratul Mahanta +1
Axions and axion-like particles are a compelling candidate for physics beyond the standard model. While many axion searches are focused on the linear coupling to photons $θF \tilde…
Time-dependent flux backgrounds in type IIB supergravity
Ahmed Rakin Kamal, Ratul Mahanta
We analytically construct families of type IIB supergravity backgrounds in ten dimensions in which the four-dimensional metric is time dependent, while the six-dimensional internal…
Dimensional Reduction and Kähler Metric for Metric Moduli in Imaginary Self-Dual Flux
Andrew R. Frey, Ratul Mahanta
Understanding which effective field theories are consistent with an ultraviolet completion in quantum gravity is an important theoretical question. Therefore, it is important to kn…
Gravitational Waves from High Temperature Strings
Andrew R. Frey, Ratul Mahanta, Anshuman Maharana +2
We study finite temperature effects in string cosmology and their potential gravitational wave signature. Expanding on our recent work arXiv:2310.11494 , we consider a general conf…
String Thermodynamics In and Out of Equilibrium: Boltzmann Equations and Random Walks
Andrew R. Frey, Ratul Mahanta, Anshuman Maharana +3
We revisit the study of string theory close to the Hagedorn temperature with the aim towards cosmological applications. We consider interactions of open and closed strings in a gas…
Early Dark Energy in Type IIB String Theory
Michele Cicoli, Matteo Licheri, Ratul Mahanta +3
Early Dark Energy (EDE) is a promising model to resolve the Hubble Tension, that, informed by Cosmic Microwave Background data, features a generalization of the potential energy us…
Modular linear differential equations for four-point sphere conformal blocks
Ratul Mahanta, Tanmoy Sengupta
We construct modular linear differential equations (MLDEs) w.r.t. subgroups of the modular group whose solutions are Virasoro conformal blocks appearing in the expansion of a cross…
Flux Vacua with Approximate Flat Directions
Michele Cicoli, Matteo Licheri, Ratul Mahanta +1
We present a novel method to obtain type IIB flux vacua with flat directions at tree level. We perform appropriate choices of flux quanta that induce relations between the flux sup…
Analyticity Domain for Off-shell Five-point Superstring Loop Amplitudes
Ritabrata Bhattacharya, Ratul Mahanta
In an earlier work arXiv:2009.0337, we showed that for arbitrary Feynman loop diagrams (with no massless internal propagators) in closed superstring field theory, a known domain ca…
Dark Radiation and the Hagedorn Phase
Andrew R. Frey, Ratul Mahanta, Anshuman Maharana
We point out that if the sector associated with the Standard Model degrees of freedom entered an open string Hagedorn phase in the early universe while the dark radiation sector wa…
Non-thermal Hot Dark Matter from Inflaton/Moduli Decay: The Momentum Distribution and Relaxing the Cosmological Mass Bound
Sukannya Bhattacharya, Subinoy Das, Koushik Dutta +3
Decay of the inflaton or moduli which dominated the energy density of the universe at early times leads to a matter to radiation transition epoch. We consider non-thermal sterile d…
Analyticity of Off-shell Green's Functions in Superstring Field Theory
Ritabrata Bhattacharya, Ratul Mahanta
We consider the off-shell momentum space Green's functions in closed superstring field theory. Recently in arXiv:1810.07197, the off-shell Green's functions -- after explicitly rem…
Crossing, Modular Averages and in WZW Models
Ratul Mahanta, Anshuman Maharana
We consider the construction of genus zero correlators of WZW models involving two Kac Moody primaries in the fundamental and two in the anti-fundamental representation f…