papers

Publications (32)

math.DG2015

On real hypersurfaces in non-flat complex space forms with a condition on the structure Jacobi operator OPERATOR

S. H. Kon, Tee-How Loo, Shiquan Ren

In this paper we prove some classification theorems of real hypersur- faces in Mn(c) satisfying certain conditions on the covariant derivative of the structure Jacobi operator. We…

gr-qc2021

How a conformally flat (GR)4 impacts Gauss-Bonnet gravity?

Avik De, Tee-How Loo, Raja Solanki +1

First and foremost, we show that a 4-dimensional conformally flat generalized Ricci recurrent spacetime is an Einstein manifold. We examine such a spacetime as a solution…

gr-qc2023

How different connections in flat FLRW geometry impact energy conditions in theory?

Ganesh Subramaniam, Avik De, Tee-How Loo +1

In this study of the modified theory of gravity in the spatially flat Friedmann-Lemaître-Robertson-Walker (FLRW) spacetime, we explore all the affine connections compatible…

math.DG2015

Generalized Sasakian space forms and Riemannian manifolds of quasi constant sectional curvature

Avik De, Tee-How Loo

In this paper, we show that a generalized Sasakian space form of dimension greater than three is either of constant sectional curvature; or a canal hypersurface in Euclidean or Min…

gr-qc2026

Perturbation Dynamics and Structure Formation in Extended Proca-Nuevo Gravity

N. S. Kavya, Avik De, Tee-How Loo

A comprehensive analysis of cosmological perturbations and structure formation is presented for the Extended Proca-Nuevo (EPN) framework, a vector-tensor extension of General Relat…

gr-qc2025

Can an Extra Degree of Freedom in Scalar-Tensor Non-Metricity Gravity Account for the Evolution of the Universe?

Ghulam Murtaza, Avik De, Andronikos Paliathanasis +1

We investigate whether the extra scalar degree of freedom that arises in the second connection class of scalar-tensor non-metricity gravity can accurately replicate and potentially…

gr-qc2023

gravity, its covariant formulation, energy conservation and phase-space analysis

Tee-How Loo, Raja Solanki, Avik De +1

In the present article we analyze the matter-geometry coupled theory of gravity. We offer the fully covariant formulation of the theory, with which we construct the correc…

gr-qc2022

Periodic cosmic evolution in gravity formalism

Parbati Sahoo, Avik De, Tee-How Loo +1

We study the periodic cosmic transit behavior of accelerated universe in the framework of symmetric teleparallelism. The exact solution of field equations is obtained by employing…

math.DG2014

Real hypersurfaces with pseudo-parallel normal Jacobi operator in complex two-plane Grassmannians

Avik De, Tee-How Loo

The objective of the present paper is to prove the non-existence of real hypersurface with pseudo-parallel normal Jacobi operator in complex two-plane Grassmannians. As a corollary…

gr-qc2026

Scalar field coupled to boundary in non-metricity: a new avenue towards dark energy

Ghulam Murtaza, Avik De, Tee-How Loo +1

While conformal transformations in metric scalar-tensor theories recover General Relativity, this feature is notably absent in standard non-metricity-based theories. We demonstrate…

gr-qc2023

On the viability of gravity models

Avik De, Tee-How Loo

In general relativity, the contracted Bianchi identity makes the field equation compatible with the energy conservation, likewise in theories of gravity. We show that this c…

gr-qc2023

Anisotropic Universe in gravity, a novel study

Tee-How Loo, M. Koussour, Avik De

theory of gravity is very recently proposed to incorporate within the action Lagrangian, the trace of the energy-momentum tensor along with the non-metricity scalar $Q…

gr-qc2021

How a projectively flat geometry regulates -gravity theory?

Tee-How Loo, Avik De, Sanjay Mandal +1

In the present paper we examine a projectively flat spacetime solution of -gravity theory. It is seen that once we deploy projective flatness in the geometry of the spacetime…

gr-qc2025

Scalar perturbation and density contrast evolution in gravity

Ganesh Subramaniam, Avik De, Tee-How Loo +1

The symmetric teleparallel theory offers an alternative gravitational formulation which can elucidate events in the early and late universe without requiring the physical existence…

gr-qc2021

A Conformally Flat Generalized Ricci Recurrent Spacetime in F(R)-Gravity

Avik De, Tee-How Loo, Raja Solanki +1

In the present paper we study a conformally flat generalized Ricci recurrent perfect fluid spacetime with constant Ricci scalar as a solution of modified -gravity theory. We…

math.DG2014

Pseudo parallel CR-submanifolds in a non-flat complex space form

Avik De, Tee-How Loo

We classify pseudo parallel proper CR-submanifolds in a non-flat complex space form with CR-dimension greater than one. With this result, the non-existence of recurrent as well as…

gr-qc2023

Cosmology of gravity in non-flat Universe

Hamid Shabani, Avik De, Tee-How Loo +1

We investigate the cosmological implications of gravity, which is a modified theory of gravity based on non-metricity, in non-flat geometry. We perform a detailed dynamical-…

gr-qc2024

Non-metricity with bounday terms: gravity and cosmology

Avik De, Tee-How Loo, Emmanuel N. Saridakis

We formulate gravity and cosmology. Such a construction is based on the symmetric teleparallel geometry, but apart form the non-metricity scalar we incorporate in the…

math.DG2017

Real hypersurfaces in complex Grassmannians of rank two with semi-parallel structure Jacobi operator

Avik De, Tee-How Loo, Changhwa Woo

We prove that there does not exist any real hypersurface in complex Grassmannians of rank two with semi-parallel structure Jacobi operator. With this result, the nonexistence of re…

math.DG2016

Hopf hypersurfaces in complex Grassmannians of rank two

Ruenn-Huah Lee, Tee-How Loo

In this paper, we study real hypersurfaces in complex Grassmannians of rank two. First, the nonexistence of mixed foliate real hypersurfaces is proven. With this result, we show th…

gr-qc2021

Energy conditions for a spacetime in -gravity

Avik De, Tee-How Loo, Simran Arora +1

The objective of the present paper is to study 4-dimensional weakly Ricci symmetric spacetimes with non-zero constant Ricci scalar. We prove that such a satisfy…

gr-qc2022

Impact of curvature based geometric constraints on theory

Tee-How Loo, Avik De, Simran Arora +1

Theories of gravity are fundamentally a relation between matter and the geometric structure of the underlying spacetime. So once we put some additional restrictions on the spacetim…

math.DG2015

Real Hypersurfaces of Type A in Complex Two-Plane Grassmannians Related to The Reeb Vector Field

Ruenn-Huah Lee, Tee-How Loo

Y. J. Suh and H. Lee (Bull. Korean. Math. Soc. 47, 551-561 (2010)) characterized real hypersurfaces of type by the invariance of vector bundle under the shape o…

math.DG2017

-principal Hopf hypersurfaces in complex quadrics

Tee-How Loo

A real hypersurface in the complex quadric is said to be -principal if its unit normal vector field is singular of type -principal…

gr-qc2023

Phase-space analysis of a novel cosmological model in theory

Hamid Shabani, Avik De, Tee-How Loo

The vanishing affine connections have been used solely while adopting the modified gravity theory to the cosmology. Consequently, researchers could not get beyond what is al…

gr-qc2025

Phase-space analysis of an anisotropic universe in gravity

Ghulam Murtaza, Avik De, Tee-How Loo +2

In this study, we analyze the anisotropic universe in gravity theory. To achieve this, we consider three specific models of gravity and rewrite the equations of m…

math.DG2014

Semi-parallel real hypersurfaces in complex two-plane Grassmannians

Tee-How Loo

We prove that there does not exist any semi-parallel real hypersurface in complex two-plane Grassmannians. With this result, the nonexistence of recurrent real hypersurfaces in com…

math.DG2017

-invariant real hypersurfaces in complex Grassmannians of rank two

Ruenn-Huah Lee, Tee-How Loo

Let be a real hypersurface in complex Grassmannians of rank two. Denote by the quaternionic Kähler structure of the ambient space, the normal bundle o…

gr-qc2022

Isotropization of locally rotationally symmetric Bianchi-I universe in -gravity

Avik De, Sanjay Mandal, J. T. Beh +2

Despite having the somewhat successful description of accelerated cosmology, the early evolution of the universe always challenges mankind. Our promising approach lies in a new cla…

gr-qc2023

Energy condition bounds on model parameters in a curved FLRW universe

Ganesh Subramaniam, Avik De, Tee-How Loo +1

In this exclusive study of the modified theory of gravity in the open and closed type Friedmann-Lemaître-Robertson-Walker (FLRW) universe model, we impose some constraints…

gr-qc2024

The cosmological significance of boundary term in non-metricity gravity

Hamid Shabani, Avik De, Tee-How Loo

Within the context of metric-affine gravity, we examine the significance of the boundary term in symmetric teleparallel gravity by employing the cosmological dynamical system analy…

gr-qc2025

Emergent Universe in f(Q) gravity theories

Hamid Shabani, Avik De, Tee-How Loo

One resolution of the ancient cosmic singularity, i.e., the Big Bang Singularity (BBS), is to assume an inflationary stage preceded by a long enough static state in which the unive…