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R. P. Malik - One of the best experts on this subject based on the ideXlab platform.
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superspace unitary operator in qed with dirac and Complex Scalar fields superfield approach
EPL, 2015Co-Authors: D Shukla, T. Bhanja, R. P. MalikAbstract:We exploit the strength of the superspace (SUSP) unitary operator to obtain the results of the application of the horizontality condition (HC) within the framework of the augmented version of the superfield formalism that is applied to the interacting systems of Abelian 1-form gauge theories where the U(1) Abelian 1-form gauge field couples to the Dirac and Complex Scalar fields in the physical four (3 + 1)-dimensions of spacetime. These interacting theories are generalized onto a (4, 2)-dimensional supermanifold that is parametrized by the four -dimensional (4D) spacetime variables and a pair of Grassmannian variables. To derive the (anti-)BRST symmetries for the matter fields, we impose the gauge-invariant restrictions (GIRs) on the superfields defined on the (4, 2)-dimensional supermanifold. We discuss various outcomes that emerge out from our knowledge of the SUSP unitary operator and its Hermitian conjugate. The latter operator is derived without imposing any operation of Hermitian conjugation on the parameters and fields of our theory from outside. This is an interesting observation in our present investigation.
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superspace unitary operator in qed with dirac and Complex Scalar fields superfield approach
arXiv: High Energy Physics - Theory, 2015Co-Authors: D Shukla, T. Bhanja, R. P. MalikAbstract:We exploit the strength of the superspace (SUSP) unitary operator to obtain the results of the application of the horizontality condition (HC) within the framework of augmented version of superfield formalism that is applied to the interacting systems of Abelian 1-form gauge theories where the U(1) Abelian 1-form gauge field couples to the Dirac and Complex Scalar fields in the physical four (3 + 1)-dimensions of spacetime. These interacting theories are generalized onto a (4, 2)-dimensional supermanifold that is parametrized by the four (3 + 1)-dimensional (4D) spacetime variables and a pair of Grassmannian variables. To derive the (anti-)BRST symmetries for the matter fields, we impose the gauge invariant restrictions (GIRs) on the superfields defined on the (4, 2)-dimensional supermanifold. We discuss various outcomes that emerge out from our knowledge of the SUSP unitary operator and its hermitian conjugate. The latter operator is derived without imposing any operation of hermitian conjugation on the parameters and fields of our theory from outside. This is an interesting observation in our present investigation.
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a generalization of the horizontality condition in the superfield approach to nilpotent symmetries for qed with Complex Scalar fields
Journal of Physics A, 2007Co-Authors: R. P. MalikAbstract:We provide a generalization of the horizontality condition of the usual superfield approach to the Becchi–Rouet–Stora–Tyutin (BRST) formalism to obtain the (anti-)BRST symmetry transformations for all the fields of a four (3 + 1)-dimensional interacting 1-form U(1) gauge theory (QED) within the framework of the augmented superfield formalism. In the above interacting gauge theory, there is an explicit coupling between the 1-form U(1) gauge field and the Complex Scalar fields. This interacting gauge field theory is considered on the (4, 2)-dimensional supermanifold parametrized by the four even spacetime variables xμ (with μ = 0, 1, 2, 3) and a pair of odd Grassmannian variables θ and . The above nilpotent (anti-)BRST symmetry transformations are obtained due to the imposition of a gauge (i.e. BRST) invariant restriction on the appropriate superfields defined on the (4, 2)-dimensional supermanifold. This restriction owes its origin to a pair of (super) covariant derivatives and their intimate connection with the 2-form (super) curvatures. The results obtained, due to the application of the horizontality condition alone, are contained in the results deduced due to the imposition of the above gauge invariant restriction.
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augmented superfield approach to unique nilpotent symmetries for Complex Scalar fields in qed
European Physical Journal C, 2006Co-Authors: R. P. MalikAbstract:The derivation of the exact and unique nilpotent Becchi–Rouet–Stora–Tyutin (BRST) and anti-BRST symmetries for the matter fields, present in any arbitrary interacting gauge theory, has been a long-standing problem in the framework of the superfield approach to the BRST formalism. These nilpotent symmetry transformations are deduced for the four (3+1)-dimensional (4D) Complex Scalar fields, coupled to the U(1) gauge field, in the framework of an augmented superfield formalism. This interacting gauge theory (i.e. QED) is considered on a six (4,2)-dimensional supermanifold parametrized by four even spacetime coordinates and a couple of odd elements of the Grassmann algebra. In addition to the horizontality condition (that is responsible for the derivation of the exact nilpotent symmetries for the gauge field and the (anti-)ghost fields), a new restriction on the supermanifold, owing its origin to the (super) covariant derivatives, has been invoked for the derivation of the exact nilpotent symmetry transformations for the matter fields. The geometrical interpretations for all the above nilpotent symmetries are discussed, too.
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a generalization of the horizontality condition in the superfield approach to nilpotent symmetries for qed with Complex Scalar fields
arXiv: High Energy Physics - Theory, 2006Co-Authors: R. P. MalikAbstract:We provide a generalization of the horizontality condition of the usual superfield approach to Becchi-Rouet-Stora-Tyutin (BRST) formalism to obtain the nilpotent (anti-)BRST symmetry transformations for all the fields of a four (3 + 1)-dimensional interacting 1-form U(1) gauge theory (QED) within the framework of the augmented superfield formalism. In the above interacting gauge theory, there is an explicit coupling between the 1-form U(1) gauge field and the Complex Scalar fields. This interacting gauge theory is considered on the (4, 2)-dimensional supermanifold parametrized by the four even spacetime variables x^\mu (with \mu = 0, 1, 2, 3) and a pair of odd Grassmannian variables \theta and \bar\theta. The above (anti-)BRST symmetry transformations are obtained due to the imposition of a gauge (i.e. BRST) invariant restriction on the (4, 2)-dimensional supermanifold. This restriction owes its origin to the (super) covariant derivatives and their intimate connections with the 2-form (super) curvatures. The results obtained, due to the application of the horizontality condition alone, are contained in the results obtained due to the imposition of the gauge (i.e. BRST) invariant restriction on the above supermanifold.
Daya Shankar Kulshreshtha - One of the best experts on this subject based on the ideXlab platform.
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charged compact boson stars and shells in the presence of a cosmological constant
Physical Review D, 2016Co-Authors: Sanjeev Kumar, Usha Kulshreshtha, Daya Shankar KulshreshthaAbstract:In this work we study the boson stars and boson shells in a theory involving massive Complex Scalar fields coupled to the U(1) gauge field and gravity in a conical potential in the presence of a cosmological constant ${\Lambda}$ which we treat as a free parameter taking positive and negative values and thereby allowing us to study the theory in the de Sitter and Anti de Sitter spaces respectively. Boson stars are found to come in two types, having either ball-like or shell-like charge density. We have studied the properties of these solutions and have also determined their domains of existence for some specific values of the parameters of the theory. Similar solutions have also been obtained by Kleihaus, Kunz, Laemmerzahl and List in a theory involving massless Complex Scalar fields coupled to the U(1) gauge field and gravity in a conical potential in the absence of a cosmological constant ${\Lambda}$.
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boson stars in a theory of Complex Scalar field coupled to gravity
arXiv: High Energy Physics - Theory, 2016Co-Authors: Sanjeev Kumar, Usha Kulshreshtha, Daya Shankar KulshreshthaAbstract:We study boson stars in a theory of Complex Scalar field coupled to Einstein gravity with the potential: $V(|\Phi|) := m^{2} |\Phi|^2 +2 \lambda |\Phi|$ (where $m^2$ and $\lambda$ are positive constant parameters). This could be considered either as a theory of massive Complex Scalar field coupled to gravity in a conical potential or as a theory in the presence of a potential which is an overlap of a parabolic and a conical potential. We study our theory with positive as well as negative values of the cosmological constant $\Lambda$. Boson stars are found to come in two types, having either ball-like or shell-like charge density. We have studied the properties of these solutions and have also determined their domains of existence for some specific values of the parameters of the theory. Similar solutions have also been obtained by Hartmann, Kleihaus, Kunz, and Schaffer, in a V-shaped Scalar potential.
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boson stars in a theory of Complex Scalar fields coupled to u 1 gauge field and gravity
arXiv: High Energy Physics - Theory, 2016Co-Authors: Sanjeev Kumar, Usha Kulshreshtha, Daya Shankar KulshreshthaAbstract:We study boson shells and boson stars in a theory of Complex Scalar field coupled to the $U(1)$ gauge field $A_{\mu}$ and Einstein gravity with the potential: $V(|\Phi|) := \frac{1}{2} m^{2} \left(|\Phi|+ a \right)^2$. This could be considered either as a theory of massive Complex Scalar field coupled to electromagnetic field and gravity in a conical potential or as a theory in the presence of a potential which is an overlap of a parabolic and a conical potential. Our theory has a positive cosmological constant $(\Lambda := 4 \pi G m^2 a^2)$. Boson stars are found to come in two types, having either ball-like or shell-like charge density. We have studied the properties of these solutions and have also determined their domains of existence for some specific values of the parameters of the theory. Similar solutions have also been obtained by Kleihaus, Kunz, Laemmerzahl and List, in a V-shaped Scalar potential.
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boson stars in a theory of Complex Scalar fields coupled to the u 1 gauge field and gravity
Classical and Quantum Gravity, 2014Co-Authors: Sanjeev Kumar, Usha Kulshreshtha, Daya Shankar KulshreshthaAbstract:We study boson shells and boson stars in a theory of a Complex Scalar field coupled to the gauge field and Einstein gravity with the potential . This could be considered either as a theory of a massive Complex Scalar field coupled to an electromagnetic field and gravity in a conical potential, or as a theory in the presence of a potential that is an overlap of a parabolic and conical potential. Our theory has a positive cosmological constant . Boson stars are found to come in two types, having either ball-like or shell-like charge density. We studied the properties of these solutions and also determined their domains of existence for some specific values of the parameters of the theory. Similar solutions have also been obtained by Kleihaus, Kunz, Laemmerzahl and List, in a V-shaped Scalar potential.
Tonatiuh Matos - One of the best experts on this subject based on the ideXlab platform.
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could galactic magnetic fields be generated by charged ultra light boson dark matter
European Physical Journal C, 2019Co-Authors: Maribel Hernandez, Ana Avilez, Tonatiuh MatosAbstract:We study the possibility that large-scale magnetic fields observed in galaxies could be produced by a dark matter halo made of charged ultra-light bosons, that arise as excitations of a Complex Scalar field described by the Klein–Gordon equation with local U(1) symmetry which introduces electromagnetic fields that minimally couple to the Complex Scalar current and act as dark virtual photons. These virtual photons have an unknown coupling constant with real virtual photons. We constrain the final interaction using the observed magnetic fields in galaxies. We use classical solutions of the Klein–Gordon–Maxwell system to describe the density profile of dark matter and magnetic fields in galaxies. We consider two cases assuming spherical and dipolar spatial symmetries. For the LSB spherical galaxy F563-V2, we test the sensitivity of the predicted rotation curves in the charged Scalar Field Dark Matter (cSFDM) model to variations of the electromagnetic coupling and using the Fisher matrix error estimator, we set a constraint over that coupling by requiring that theoretical rotation curves lay inside the $$1\sigma $$ confidence region of observational data. We find that cSFDM haloes generate magnetic fields of the order of $$\mu G$$ and reproduce the observed rotation curves of F563-V2 if the ultra-light boson has a charge $$\sim <10^{-13}e$$ for the monopole-like density profile and $$\sim <10^{-14}e$$ for the dipole-like one.
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could primordial galactic magnetic fields be generated by charged ultra light boson dark matter
arXiv: General Relativity and Quantum Cosmology, 2018Co-Authors: Maribel Hernandez, Ana Avilezlopez, Tonatiuh MatosAbstract:In this work we study the possibility that primordial magnetic fields observed in galaxies could be produced by a dark matter halo made of charged ultra-light bosons. In the model, we assume that ultra-light bosons arise as excitations of a Complex Scalar field described by the Klein-Gordon equation with local $U(1)$ symmetry which introduces electromagnetic fields that minimally couple to the Complex Scalar current. We use classical solutions of the Klein-Gordon-Maxwell system to describe the density profile of dark matter and magnetic fields in the galaxies. We consider two cases assuming spherical and dipolar spatial symmetries respectively. For the particular case of the LSB spherical galaxy F563, we test the sensitivity of the predicted rotation curves in the charged Scalar field dark matter (cSFDM) model to variations of the electromagnetic coupling and, by using the Fisher matrix error estimator, we set a constraint over that coupling by requiring that theoretical rotation curves lay inside the $1\sigma$ confidence region of observational data . We find that cSFDM haloes are able to generate magnetic fields of the order of $\mu G$ and reproduce the observed rotation curves of F563-V2 at the same time if the ultra-light boson has a charge lower than $\sim 10^{-13}e$ for the monopole-like density profile and lower than $10^{-14}e$ for the dipole-like one.
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covariant theory of bose einstein condensates in curved spacetimes with electromagnetic interactions the hydrodynamic approach
European Physical Journal Plus, 2017Co-Authors: Pierrehenri Chavanis, Tonatiuh MatosAbstract:We develop a hydrodynamic representation of the Klein-Gordon-Maxwell-Einstein equations. These equations combine quantum mechanics, electromagnetism, and general relativity. We consider the case of an arbitrary curved spacetime, the case of weak gravitational fields in a static or expanding background, and the nonrelativistic (Newtonian) limit. The Klein-Gordon-Maxwell-Einstein equations govern the evolution of a Complex Scalar field, possibly describing self-gravitating Bose-Einstein condensates, coupled to an electromagnetic field. They may find applications in the context of dark matter, boson stars, and neutron stars with a superfluid core.
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study of symmetry breaking of charged Scalar field hydrodynamic version
Journal of Physics: Conference Series, 2014Co-Authors: Tonatiuh Matos, M A RodriguezmezaAbstract:We rewrite the Klein-Gordon (KG) equation for a Complex Scalar field as a new Gross-Pitaevskii (GP)-like equation. The potential of the Scalar field is a mexican-hat potential and the field is in a thermal bath with one loop contribution. We interpret the new GP equation as a finite temperature generalization of the GP equation for a charged field. We find its hydrodynamic version as well and using it, we derive the corresponding thermodynamics. We also obtain a generalized first law for a charged Bose-Einstein Condensate (BEC).
Michael J Ramseymusolf - One of the best experts on this subject based on the ideXlab platform.
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standard model with a Complex Scalar singlet cosmological implications and theoretical considerations
Physical Review D, 2018Co-Authors: Chengwei Chiang, Michael J Ramseymusolf, Eibun SenahaAbstract:We analyze the theoretical and phenomenological considerations for the electroweak phase transition and dark matter in an extension of the standard model with a Complex Scalar singlet (cxSM). In contrast with earlier studies, we use a renormalization group improved Scalar potential and treat its thermal history in a gauge-invariant manner. We find that the parameter space consistent with a strong first-order electroweak phase transition (SFOEWPT) and present dark matter phenomenological constraints is significantly restricted compared to results of a conventional, gauge-noninvariant analysis. In the simplest variant of the cxSM, recent LUX data and a SFOEWPT require a dark matter mass close to half the mass of the standard model-like Higgs boson. We also comment on various caveats regarding the perturbative treatment of the phase transition dynamics.
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Complex Scalar singlet dark matter vacuum stability and phenomenology
Physical Review D, 2012Co-Authors: Matthew Gonderinger, Michael J Ramseymusolf, Hyungjun LimAbstract:We analyze one-loop vacuum stability, perturbativity, and phenomenological constraints on a Complex singlet extension of the standard model Scalar sector containing a Scalar dark matter candidate. We study vacuum stability considerations using a gauge-invariant approach and compare with the conventional gauge-dependent procedure. We show that, if new physics exists at the TeV scale, the vacuum stability analysis and experimental constraints from the dark matter sector, electroweak precision data, and LEP allow both a Higgs-like Scalar in the mass range allowed by the latest results from CMS and ATLAS and a lighter singlet-like Scalar with weak couplings to standard model particles. If instead no new physics appears until higher energy scales, there may be significant tension between the vacuum stability analysis and phenomenological constraints (in particular electroweak precision data) to the extent that the Complex singlet extension with light Higgs and singlet masses would be ruled out. We comment on the possible implications of a Scalar with ∼125 GeV mass and future ATLAS invisible decay searches.
Luis E Padilla - One of the best experts on this subject based on the ideXlab platform.
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Complex Scalar field reheating and primordial black hole production
Journal of Cosmology and Astroparticle Physics, 2021Co-Authors: Karim Carrion, Juan Carlos Hidalgo, Ariadna Montiel, Luis E PadillaAbstract:We study perturbations of a Complex Scalar field during reheating with no self-interaction in the regime $\mu \gg H$, when the Scalar field has a fast oscillatory behaviour (close to a pressure-less fluid). We focus on the precise determination of the instability scale and look at the probability that unstable fluctuations may form Primordial Black Holes (PBHs). After deriving such probability, we impose restrictions on the duration of the fast oscillations period by looking at constraints to the abundance of PBHs via Planck relics.
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Complex Scalar field reheating and primordial black hole production
arXiv: Cosmology and Nongalactic Astrophysics, 2021Co-Authors: Karim Carrion, Juan Carlos Hidalgo, Ariadna Montiel, Luis E PadillaAbstract:We study perturbations of a Complex Scalar field during reheating with no self-interaction in the regime $ \mu \gg H$, when the Scalar field has a fast oscillatory behaviour (close to a pressure-less fluid). We focus on the precise determination of the instability scale and find it differs from that associated with a real Scalar field. We further look at the probability that unstable fluctuations form Primordial Black Holes (PBHs) obtaining a significant production of tiny PBHs which quickly evaporate and may subsequently leave a population of Planck-mass relics. We finally impose restrictions on the duration and energy scale of the fast oscillations period by considering that such relics constitute, at most, the totality of dark matter in the Universe.