arXiv subjects

V. Sunil Kumar

Publications and source records attributed to V. Sunil Kumar.

5 recordsLinked to original sources

arXiv2012

Impact of a light stabilized radion in supernovae cooling

In the Randall-Sundrum model where the Standard Model fields are confined to the TeV brane located at the orbifold point $θ= π$ and the gravity peaks at the Planck brane located at $θ= 0$, the stabilized modulus (radion) field is required to stabilize the size of the fifth spatial dimension. It can be produced copiously inside the supernova core due to nucleon-nucleon bremstrahlung, electron-positron and plasmon-plasmon annihilations, which then subsequently decays to neutrino-antineutrino pair and take away the energy released in SN1987A explosion. Assuming that the supernovae cooling rate $\dot{\varepsilon} \le 7.288\times 10^{-27} \rm{GeV}$, we find the lower bound on the radion vev $\vphi \sim 9.0$ TeV, 2.2 TeV and 0.9 TeV corresponding to the radion mass $m_ϕ= 5$ GeV, 20 GeV and 50 GeV, respectively.

hep-ph↗

arXiv2004

Skyrmion formation in 1+1 dimensions with chemical potential

Formation of topological objects during phase transitions has been discussed extensively in literature. In all these discussions defects and anti-defects form with equal probabilities. In contrast, many physical situations, such as formation of baryons in relativistic heavy-ion collisions at present energies, flux tube formation in superconductors in the presence of external magnetic field, and formation of superfluid vortices in a rotating vessel, require a mechanism which can bias (say) defects over anti-defects. Such a bias can crucially affect defect-anti-defect correlations, apart from its effects on defect density. In this paper we initiate an investigation for the basic mechanism of biased formation of defects. For Skyrmions in 1+1 dimensions, we show that incorporation of a chemical potential term in the effective potential leads to a domain structure where order parameter is spatially varying. We show that this leads to biased formation of Skyrmions.

hep-ph↗

arXiv2004

Supersymmetric Quantum Mechanics on Non-Commutative Plane

We study the Pauli equation on non-commutative plane. It is shown that the Supersymmetry algebra holds to all orders in the non-commutative parameter $θ$ in case the gyro-magnetic ratio $g$ is 2. Using Seiberg-Witten map, the first order in $θ$ correction to the spectrum is obtained in the case of uniform magnetic field. We find that the eigenstates in the non-commutative case are identical to the commutative case provided the magnetic field $B$ is everywhere replaced by $B(1+Bθ)$.

hep-th↗

arXiv2002

Jordan-Schwinger realizations of three-dimensional polynomial algebras

A three-dimensional polynomial algebra of order $m$ is defined by the commutation relations $[P_0, P_\pm]$ $=$ $\pm P_\pm$, $[P_+, P_-]$ $=$ $ϕ^{(m)}(P_0)$ where $ϕ^{(m)}(P_0)$ is an $m$-th order polynomial in $P_0$ with the coefficients being constants or central elements of the algebra. It is shown that two given mutually commuting polynomial algebras of orders $l$ and $m$ can be combined to give two distinct $(l+m+1)$-th order polynomial algebras. This procedure follows from a generalization of the well known Jordan-Schwinger method of construction of $su(2)$ and $su(1,1)$ algebras from two mutually commuting boson algebras.

math-ph↗

arXiv2001

Three dimensional quadratic algebras: Some realizations and representations

Four classes of three dimensional quadratic algebras of the type $\lsb Q_0 , Q_\pm \rsb$ $=$ $\pm Q_\pm$, $\lsb Q_+ , Q_- \rsb$ $=$ $aQ_0^2 + bQ_0 + c$, where $(a,b,c)$ are constants or central elements of the algebra, are constructed using a generalization of the well known two-mode bosonic realizations of $su(2)$ and $su(1,1)$. The resulting matrix representations and single variable differential operator realizations are obtained. Some remarks on the mathematical and physical relevance of such algebras are given.

math-ph↗