145 citations · 2.1k across the 96 of their papers we have counts for
52 papers · 1 filter
Hidden quantum-informatic symmetries of quasi-de Sitter backgrounds
Suddhasattwa Brahma, Jaime Calderon-Figueroa, Xiancong Luo +1
We investigate how degeneracies in quasi-de Sitter backgrounds, in the sense of Wands' duality, are reflected in real-space quantum correlations of primordial perturbations. Using…
Multi-Matrix Quantum Mechanics, Collective Fields and Emergent Space
Yue Lei, Suddhasattwa Brahma, Robert Brandenberger
We study quantum mechanics of bosonic multi-matrix Lagragians in the collective field framework, with particular emphasis on three matrix models. We derive the effective Hamiltonia…
Transient de Sitter and Quasi de Sitter States in SO(32) and E_8 x E_8 Heterotic String Theories
Keshav Dasgupta, Suddhasattwa Brahma, Bohdan Kulinich +3
One of the long-standing puzzles in string theory has been on the existence of a four-dimensional de Sitter and quasi de Sitter configurations, the latter being defined with a temp…
Heterotic Warm Inflation
Arjun Berera, Heliudson Bernardo, Suddhasattwa Brahma +3
We propose a two-field model of warm inflation motivated by a heterotic string construction, involving an axion and a dilaton-like scalar field with non-trivial kinetic mixing. Gau…
The early universe is -ing
Arjun Berera, Suddhasattwa Brahma, Zizang Qiu +2
The recently released data from the (ACT) confirms that the primordial scalar spectrum is extremely flat. This, together with current upper b…
Probing the self-coherence of primordial quantum fluctuations with complexity
Arpan Bhattacharyya, Suddhasattwa Brahma, S. Shajidul Haque +2
A smoking gun for our current paradigm of the early universe would be direct evidence for the quantum mechanical origin of density perturbations which are conjectured to seed the l…
de Sitter Excited State in Heterotic E_8 x E_8 Theory
Suddhasattwa Brahma, Keshav Dasgupta, Bohdan Kulinich +3
We devise a novel duality sequence to study late-time cosmology in the heterotic E_8 x E_8 setup of Horava and Witten with dynamical walls that are moving towards each other. Surpr…
The special case of slow-roll attractors in de Sitter: Non-Markovian noise and evolution of entanglement entropy
Suddhasattwa Brahma, Jaime Calderón-Figueroa, Xiancong Luo +1
We analyse the evolution of the reduced density matrix of inflationary perturbations, coupled to a heavy entropic field via the leading-order term within the Effective Field Theory…
Collective field theory of gauged multi-matrix models: Integrating out off-diagonal strings
Suddhasattwa Brahma, Robert Brandenberger, Keshav Dasgupta +2
We study a two-matrix toy model with a BFSS-like interaction term using the collective field formalism. The main technical simplification is obtained by gauge-fixing first, and int…
Benchmarking quantum chaos from geometric complexity
Arpan Bhattacharyya, Suddhasattwa Brahma, Satyaki Chowdhury +1
Recent studies have shown that there is a strong interplay between quantum complexity and quantum chaos. In this work, we consider a new method to study geometric complexity for in…
Glauber-Sudarshan States, Wave Functional of the Universe and the Wheeler-De Witt equation
Suddhasattwa Brahma, Keshav Dasgupta, Fangyi Guo +1
One of the pertinent question in the analysis of de Sitter as an excited state is what happens to the Glauber-Sudarshan states that are off-shell, i.e. the states that do not satis…
Finite complexity of the de Sitter vacuum
Suddhasattwa Brahma, Lucas Hackl, Moatsem Hassan +1
The ER=EPR conjecture states that quantum entanglement between boundary degrees of freedom leads to the emergence of bulk spacetime itself. Although this has been tested extensivel…
Time-convolutionless cosmological master equations: Late-time resummations and decoherence for non-local kernels
Suddhasattwa Brahma, Jaime Calderón-Figueroa, Xiancong Luo
We revisit a simple toy model of two scalar fields in de Sitter space, playing the roles of "system" and "environment" degrees of freedom, which interact with each other. We show t…
The Early Universe as an Open Quantum System: Complexity and Decoherence
Arpan Bhattacharyya, Suddhasattwa Brahma, S. Shajidul Haque +2
In this work, we extend previous results, demonstrating how complexity in an open quantum system can identify decoherence between two fields, even in the presence of an acceleratin…
IKKT thermodynamics and early universe cosmology
Samuel Laliberte, Suddhasattwa Brahma
Matrix theory is a proposed non-perturbative definition of superstring theory in which space is emergent. Recently, it was shown that space-time can emerge with a scale-invariant s…
Momentum-space entanglement entropy in de Sitter
Suddhasattwa Brahma, Jaime Calderón-Figueroa, Moatasem Hassan +1
We study the momentum-space entanglement between the sub- and super-Hubble modes of a spectator scalar field, with a cubic interaction, in de Sitter space. Momentum-space en…
Resurgence of a de Sitter Glauber-Sudarshan State: Nodal Diagrams and Borel Resummation
Suddhasattwa Brahma, Keshav Dasgupta, Mir-Mehedi Faruk +4
We show that an explicit construction of a four-dimensional de Sitter space may be performed using a diagrammatic approach via nodal diagrams emanating from the path integral repre…
BFSS Matrix Model Cosmology: Progress and Challenges
Suddhasattwa Brahma, Robert Brandenberger, Samuel Laliberte
We review a proposal to obtain an emergent metric space-time and an emergent early universe cosmology from the BFSS matrix model. Some challenges and directions for future research…
Spontaneous symmetry breaking in the BFSS model: Analytical results using the Gaussian expansion method
Suddhasattwa Brahma, Robert Brandenberger, Samuel Laliberte
We apply the Gaussian expansion method to the BFSS matrix model in the high temperature limit. When the (Euclidean) BFSS action is expanded about a Gaussian ansatz, it is shown tha…
Emergent Metric Space-Time from Matrix Theory
Suddhasattwa Brahma, Robert Brandenberger, Samuel Laliberte
The IKKT matrix model yields an emergent space-time. We further develop these ideas and give a proposal for an emergent metric. Based on previous numerical studies of this model, w…
Quantum corrections to the primordial tensor spectrum: Open EFTs & Markovian decoupling of UV modes
Suddhasattwa Brahma, Arjun Berera, Jaime Calderón-Figueroa
Perturbative quantum corrections to primordial power spectra are important for testing the robustness and the regime of validity of inflation as an effective field theory. Although…
Emergent Early Universe Cosmology from BFSS Matrix Theory
Suddhasattwa Brahma, Robert Brandenberger, Samuel Laliberte
The BFSS matrix model is a suggested non-perturbative definition of string theory. Starting from a thermal state of this matrix model, we show how space and time can emerge dynamic…
de Sitter Space as a Glauber-Sudarshan State: II
Heliudson Bernardo, Suddhasattwa Brahma, Keshav Dasgupta +2
We provide further evidence to support the fact that a four-dimensional effective field theory description with de Sitter isometries in IIB string theory, overcoming the no-go and…
Emergent Cosmology from Matrix Theory
Suddhasattwa Brahma, Robert Brandenberger, Samuel Laliberte
Matrix theory is a proposed non-perturbative definition of superstring theory in which space is emergent. We begin a study of cosmology in the context of matrix theory. Specificall…