116920223
A potential approach to spinor quarks
SummaryBy choosing a special potential for a Dirac spinor, one can obtain linear fermionic Regge trajectories without parity doubling.RiassuntoSe si sccglie un potenziale speciale per gli spinori di Dirac, si possono ottenere traiettorie di Regge lineari per i fermioni, senza raddoppio della parità.РеэюмеВыбирая специальный потенциал для спинора Дирака, мы можем получить линейные фермионные траектории Редже беэ удвоения четности.
12642120
Anti-de Sitter Black Holes, Thermal Phase Transition and Holography in Higher Curvature Gravity
We study anti\char21{}de Sitter black holes in the Einstein-Gauss-Bonnet and the generic ${R}^{2}$ gravity theories, evaluate different thermodynamic quantities, and also examine the possibilities of Hawking-Page\char21{}type thermal phase transitions in these theories. In the Einstein theory, with a possible cosmological term, one observes a Hawking-Page phase transition only if the event horizon is a hypersurface of positive constant curvature $(k=1).$ But, with the Gauss-Bonnet and/or the $(\mathrm{Riemann}{)}^{2}$ interaction terms, there may occur a similar phase transition for a horizon of negative constant curvature $(k=\ensuremath{-}1).$ We examine the finite coupling effects, and find that $Ng5$ could trigger a Hawking-Page phase transition in the latter theory. For the Gauss-Bonnet black holes, one relates the entropy of the black hole to a variation of the geometric property of the horizon based on the first law and Noether charge. With a $(\mathrm{Riemann}{)}^{2}$ term, however, we can do this only approximately, and the two results agree when ${r}_{H}\ensuremath{\gg}L,$ the size of the horizon is much bigger than the AdS curvature scale. We establish some relations between bulk data associated with the AdS black hole and boundary data defined on the horizon of the AdS geometry. Following a heuristic approach, we estimate the difference between Hubble entropy $({\mathcal{S}}_{H})$ and Bekenstein-Hawking entropy $({\mathcal{S}}_{\mathrm{BH}})$ with a $(\mathrm{Riemann}{)}^{2}$ term, which, for $k=0$ and $k=\ensuremath{-}1,$ implies ${\mathcal{S}}_{\mathrm{BH}}l~{\mathcal{S}}_{H}.$
11333859
No ghost state of Gauss–Bonnet interaction in warped backgrounds
Abstract A general solution to the Einstein field equations with the Gauss–Bonnet (GB) term in an AdS 5 bulk background implies that the GB coupling α can take either sign (+ or −), though a positive α will be more meaningful. By considering linearized gravity with the GB term in the Randall–Sundrum (RS) a singular 3-brane model, we study the gravitational interactions between matter sources localized on the brane. With correctly defined boundary conditions on the brane, we find a smooth behavior of graviton propagators and hence the zero-mode solution as a 4d massless graviton localized on the brane with correct momentum and tensor structures. The coupling α modifies the graviton propagators both on the brane and in the bulk. The issue on ghost state of the GB term is resolved, and we find that there is no real ghost (negative norm) state of the GB term in the RS single brane picture. The latter condition leads to a consistency in the coupling between the brane matter and the bulk gravity. We also elucidate about the possibilities for behavior of a test particle on the brane and in the bulk.
12520342
DIRAC QUANTIZATION OF RESTRICTED QCD
We discuss the quantization of the restricted gauge theory of SU(2) QCD regarding it as a second-class constraint system, and construct the BRST symmetry of the constrained system in the framework of the improved Dirac quantization scheme. Our analysis tells that one could efficiently quantize the restricted QCD under the BRST symmetry as if it is a first-class constraint system.
118204832
Gauge Invariance and Stability of SNO vacuum in QCD
We point out a critical defect in the calculation of the functional determinant of the gluon loop in the Savvidy-Nielsen-Olesen (SNO) effective action. We prove that the gauge invariance naturally exclude the unstable tachyonic modes from the gluon loop integral. This guarantees the stability of the magnetic condensation in QCD.
16229635
Dilatonic dark matter and unified cosmology: a new paradigm
We study the possibility that the dilaton - the fundamental scalar field which exists in all existing unified field theories - plays the role of the dark matter of the universe. We find that the condition for the dilaton to be the dark matter strongly restricts its mass to be around 0.5 keV or 270 MeV. For the other mass ranges, the dilaton either undercloses or overcloses the universe. The 0.5 keV dilaton has a free-streaming distance of about 1.4 Mpc and becomes an excellent candidate for warm dark matter, while the 270 MeV one has a free-streaming distance of about 7.4 pc and becomes cold dark matter. We discuss the possible ways to detect the dilaton experimentally.
121443233
MONOPOLE CONDENSATION AND MASS GAP IN SU(3) QCD
We demonstrate the monopole condensation in SU(3) QCD. We first discuss the gauge independent and Weyl symmetric Abelian (Cho-Duan-Ge) decomposition of the SU(3) QCD, and present a new gauge invariant integral expression of the one-loop effective action which has no infrared divergence. Integrating it gauge invariantly imposing the color reflection invariance ("the C-projection") we show that the effective potential generates the stable monopole condensation which generates the mass gap.
121563333
C-projection and monopole condensation in QCD
We show that the monopole condensation is responsible for the confinement. To demonstrate this we present a new gauge invariant integral expression of the one-loop QCD effective action which has no infra-red divergence, and show that the color reflection invariance ("the C-projection") assures the gauge invariance and the stability of the monopole condensation.