158 citations · 3.2k across the 126 of their papers we have counts for
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Confinement and Deconfinement in Gauge Theories: A Quantum Field Theory
A. P. Balachandran
After a brief recount of small and large gauge transformations and the nature of observables, we discuss superselection sectors in gauge theories. There are an infinity of them, cl…
Review of Twisted Poincare Symmetry
A. P. Balachandran, S. Kurkcuoglu, S. Vaidya
This article reviews the construction and some applications of twisted Poincare-covariant quantum fields on the Moyal plane. The Drinfeld twist, which plays a key mathematical role…
Superselection, Boundary Algebras and Duality in Gauge Theories
A. P. Balachandran, V. P. Nair, A. Pinzul +2
We consider the generators of gauge transformations with test functions which do not vanish on the boundary of a spacelike region of interest. These are known to generate the edge…
Aspects of Boundary Conditions for Nonabelian Gauge Theories
A. P. Balachandran, V. P. Nair, Sachindeo Vaidya
The boundary values of the time-component of the gauge potential form externally specifiable data characterizing a gauge theory. We point out some consequences such as reduced symm…
The Gauss Law: A Tale
A. P. Balachandran, A. F. Reyes-Lega
The Gauss law plays a basic role in gauge theories, enforcing gauge invariance and creating edge states and superselection sectors. This article surveys these aspects of the Gauss…
An Action for the Infrared Regime of Gauge Theories and the Problem of Color Transformations
A. P. Balachandran, V. P. Nair
It has been known for a while that there is spontaneous breaking of Lorentz symmetry in the nonzero charged sectors of quantum electrodynamics due to the infrared problem of soft p…
Novel Edge States in Self-Dual Gravity
A. P. Balachandran, Amilcar R. de Quieroz, M. Arshad Momen
In contrast to the Einstein-Hilbert action, the action for self-dual gravity contains vierbeins. They are eleminated at the level of observables by an gauge cond…
Entangled Scent of a Charge
M. Asorey, A. P. Balachandran, F. Lizzi +1
We argue that the ground state of a field theory, in the presence of charged particles, becomes an entangled state involving an infinity of soft photons. The quantum field vacuum i…
Localization in the Rindler Wedge
M. Asorey, A. P. Balachandran, G. Marmo +1
One of the striking features of QED is that charged particles create a coherent cloud of photons. The resultant coherent state vectors of photons generate a non-trivial representat…
Equations of Motion as Covariant Gauss Law: The Maxwell-Chern-Simons Case
A. P. Balachandran, Arshad Momen, Amilcar R. de Queiroz
Time-independent gauge transformations are implemented in the canonical formalism by the Gauss law which is not covariant. The covariant form of Gauss law is conceptually important…
Matrix Model of QCD: Edge Localized Glue Balls and Phase Transitions
Nirmalendu Acharyya, A. P. Balachandran
In a matrix model of pure Yang-Mills theory, boundaries emerge in the space of and the Hamiltonian requires boundary conditions. We show the…
Equations of Motion as Constraints: Superselection Rules, Ward Identities
M. Asorey, A. P. Balachandran, F. Lizzi +1
The meaning of local observables is poorly understood in gauge theories, not to speak of quantum gravity. As a step towards a better understanding we study asymptotic (infrared) tr…
Glueball Spectra from a Matrix Model of Pure Yang-Mills Theory
Nirmalendu Acharyya, A. P. Balachandran, Mahul Pandey +2
We present variational estimates for the low-lying energies of a simple matrix model that approximates Yang-Mills theory on a three-sphere of radius . By fixing the grou…
BRST Symmetry: Boundary Conditions and Edge States in QED
Nirmalendu Acharyya, A. P. Balachandran, Verónica Errasti Díez +2
In manifolds with spatial boundary, BRST formalism can be used to quantize gauge theories. We show that, in a gauge theory, only a subset of all the boundary conditions allo…
QCD Breaks Lorentz Invariance and Colour
A. P. Balachandran
In a previous work [1], we have argued that the algebra of non-abelian superselection rules is spontaneously broken to its maximal abelian subalgebra, that is, the algebra generate…
Supersymmetry: Boundary Conditions and Edge States
Nirmalendu Acharyya, Manuel Asorey, A. P. Balachandran +1
When spatial boundaries are inserted, SUSY can be broken. We show that in an supersymmetric theory, all the boundary conditions allowed by self-adjointness of the H…
A Matrix Model for QCD
A. P. Balachandran, Sachindeo Vaidya, Amilcar R. de Queiroz
Gribov's observation that global gauge fixing is impossible has led to suggestions that there may be a deep connection between gauge-fixing and confinement. We find an unexpected r…
A Matrix Model for QCD: QCD Colour is Mixed
A. P. Balachandran, Amilcar de Queiroz, Sachindeo Vaidya
We use general arguments to show that coloured QCD states when restricted to gauge invariant local observables are mixed. This result has important implications for confinement: a…
Spontaneous Lorentz Violation: The Case of Infrared QED
A. P. Balachandran, S. Kurkcuoglu, A. R. de Queiroz +1
It is by now clear that infrared sector of QED has an intriguingly complex structure. Based on earlier pioneering works on this subject, two of us recently proposed a simple modifi…
Entanglement and Particle Identity: A Unifying Approach
A. P. Balachandran, T. R. Govindarajan, Amilcar R. de Queiroz +1
It has been known for some years that entanglement entropy obtained from partial trace does not provide the correct entanglement measure when applied to systems of identical partic…
Quantum Entropic Ambiguities: Ethylene
A. P. Balachandran, Amilcar R. de Queiroz, S. Vaidya
In a quantum system, there may be many density matrices associated with a state on an algebra of observables. For each density matrix, one can compute its entropy. These are in gen…
Spontaneous Lorentz Violation in Gauge Theories
A. P. Balachandran, S. Vaidya
Frohlich, Morchio and Strocchi long ago proved that Lorentz invariance is spontaneously broken in QED because of infrared effects. We develop a simple model where consequences of t…
Entropy of Quantum States: Ambiguities
A. P. Balachandran, A. R. de Queiroz, S. Vaidya
The von Neumann entropy of a generic quantum state is not unique unless the state can be uniquely decomposed as a sum of extremal or pure states. As pointed out to us by Sorkin, th…
Quantum Physics and Fluctuating Topologies: Survey
M. Asorey, A. P. Balachandran, G. Marmo +4
The spin-statistics connection, quantum gravity and other physical considerations suggest that classical space-time topology is not an immutable attribute and can change in quantum…