arXiv subjects

M. Tsuda

Publications and source records attributed to M. Tsuda.

15 recordsLinked to original sources

arXiv2009

On vacuum structures of N = 2 LSUSY QED equivalent to N = 2 NLSUSY model

The vacuum structure of N = 2 linear supersymmetry (LSUSY) invariant QED, which is equivalent to N = 2 nonlinear supersymmetry (NLSUSY) model, is studied explicitly in two dimensional space-time (d = 2). Two different isometries SO(1,3) and SO(3,1) appear for the vacuum field configuration corresponding to the various parameter regions. Two different field configurations of SO(3,1) isometry describe the two different physical vacua, i.e. one breaks spontaneously both U(1) and SUSY and the other breaks spontaneously SUSY alone.

hep-th↗

arXiv2007

Low energy particle physics and cosmology of nonlinear supersymmetric general relativity

We show a low energy physical meaning of nonlinear supersymmetric general relativity (NLSUSY GR) in asymptotic Riemann-flat space-time by studying the vacuum structure of N = 2 linear supersymmetry (LSUSY) invariant QED, which is equivalent to N = 2 NLSUSY model, in two dimensional space-time. Two different vacuum field configurations of SO(3,1) isometry describe the two different physical vacua, i.e. one breaks spontaneously both U(1) and SUSY and the other breaks spontaneously SUSY alone, where the latter elucidates the mysterious relations between the cosmology and the (low energy) particle physics and gives a new insight into the origin of mass.

hep-th↗

arXiv2004

New Einstein-Hilbert-type Action and Superon-Graviton Model(SGM) of Nature

A nonlinear supersymmetric(NLSUSY) Einstein-Hilbert(EH)-type new action for unity of nature is obtained by performing the Einstein gravity analogue geomtrical arguments in high symmetry spacetime inspired by NLSUSY. The new action is unstable and breaks down spontaneously into E-H action with matter in ordinary Riemann spacetime. All elementary particles except graviton are composed of the fundamental fermion "superon" of Nambu-Goldstone(NG) fermion of NLSUSY and regarded as the eigenstates of SO(10) super-Poincaré (SP) algebra, called superon-graviton model(SGM) of nature. Some phenomenological implications for the low energy particle physics and the cosmology are discussed. The linearization of NLSUSY including N=1 SGM action is attempted explicitly to obtain the linear SUSY local field theory, which is equivalent and renormalizable.

hep-th↗

arXiv2003

Toward linearization of nonlinear supersymmetric Einstein-Hilbert-type action of superon-graviton model(SGM)

We attempt the linearization of the nonlinear supersymmetry encoded in the Einstein-Hilbert-type action {\it superon-graviton model(SGM)} describing the nonlinear supersymmetric gravitational interaction of Nambu-Goldstone fermion {\it superon}. We discuss the linearizaton procedure in detail by the heuristic arguments referring to supergravity, in which particular attentions are paid to the local Lorentz invariance in the minimal interaction. We show explicitly up to the leading order that 80(bosons)+80(fermions) may be the minimal off-shell supermultiplet of the linearized theory.

hep-th↗

arXiv2003

On linearization of superon-graviton model(SGM)

Referring to the supermultiplet of N=1 supergravity (SUGRA) the linearization of N=1 SGM action describing the nonlinear supersymmetric (NL SUSY) gravitational interaction of superon (Nambu-Goldstone fermion) is attempted. The field contents of on-shell SUGRA supermultiplet are realized as the composites, though they have new SUSY transformations which closes on super-Poincaré algebra. Particular attentions are paid to the local Lorentz invariance.

hep-th↗

arXiv2003

Linearizing superon-graviton model(SGM)

We attempt the linearization of N=1 SGM action describing the nonlinear supersymmetric gravitational interaction of superon(Nambu-Goldstone fermion). We find that 80+80 field contents may give the off-shell supermultiplet of the supergravity-like linearized theory and they are realized explicitly up to $O(ψ^2)$ as the composites, though they have modified SUSY transformations which closes on super-Poincaré algebra. Particular attentions are paid to the local Lorentz invariance in the minimal interaction.

hep-th↗

arXiv2002

Superon-graviton model and supersymmetric structure of spacetime and matter

A new Einstein-Hilbert type (SGM) action describing gravitational interaction of Nambu-Goldstone(N-G) fermion of nonlinear supersymmetry(NL SUSY) is obtained by performing the Einstein gravity analogue geometrical arguments in high symmetric four dimensional (SGM) spacetime. All elementary particles except graviton are regarded as the composite eigenstates of SO(10) super-Poincaré algebra(SPA) composed of the fundamental N-G fermion ``superons'' of NL SUSY. Some phenomenological implications of the composite picture of SGM, the linearlization of SGM and N = 2 Volkov-Akulov model are discussed.

hep-th↗

arXiv2002

Linearizing N = 2 Nonlinear Supersymmetry

We investigate for the N = 2 supersymmetry (SUSY) a relation between a vector supermultiplet of the linear SUSY and the Volkov-Akulov model of the nonlinear SUSY. We express component fields of the vector supermultiplet in terms of Nambu-Goldstone fermion fields at the leading orders in a SUSY invariant way, and show the vector nature of the U(1) gauge field explicitly. A relation of the actions for the two models is also discussed briefly.

hep-th↗

arXiv2002

Linearization of N = 2 Nonlinear Supersymmetry and Spontaneous Supersymmetry Breaking Parameters

We show explicitly by the heuristic and practical arguments that for $N = 2$ supersymmetry (SUSY) a SUSY invariant relation between component fields of a vector supermultiplet of linear SUSY and Nambu-Goldstone fermions of the Volkov-Akulov model of nonlinear SUSY is written by using only three arbitrary dimensionless parameters, which can be recasted as the vacuum expectation values of auxiliary fields in the vector supermultiplet.

hep-th↗

arXiv2001

On Linearization of N=1 Nonlinear Supersymmetry

The N=1 Volkov-Akulov model of nonlinear supersymmetry is explicitly related to a vector supermultiplet model with a Fayet-Iliopoulos D term of linear supersymmetry. The physical significance of the results is discussed briefly.

hep-th↗

arXiv1996

Structure of the field equations in N = 1 chiral supergravity

We study the structure of linearized field equations in $N = 1$ chiral supergravity (SUGRA) with a complex tetrad, as a preliminary to introducing additional auxiliary fields in order that the supersymmetry (SUSY) algebra close off shell. We follow the first-order formulation we have recently constructed using the method of the usual $N = 1$ SUGRA. In particular, we see how the real and imaginary parts of the complex tetrad are coupled to matter fields in the weak field approximation. Starting from the linearized (free) theory of $N = 1$ chiral SUGRA, we then construct a Lagrangian which is invariant under local SUSY transformations to zeroth order of the gravitational constant, and compare the results with the linearized field equations.

gr-qc↗

arXiv1996

Supersymmetry algebra in N = 1 chiral supergravity

We consider the supersymmetry (SUSY) transformations in the chiral Lagrangian for $N = 1$ supergravity (SUGRA) with the complex tetrad following the method used in the usual $N = 1$ SUGRA, and present the explicit form of the SUSY trasformations in the first-order form. The SUSY transformations are generated by two independent Majorana spinor parameters, which are apparently different from the constrained parameters employed in the method of the 2-form gravity. We also calculate the commutator algebra of the SUSY transformations on-shell.

gr-qc↗

arXiv1996

Consistency of matter field equations in Ashtekar formulation

The chiral Lagrangian including more than two spin-3/2 fields becomes complex in general when the self-dual connection satisfies its equation of motion, and the imaginary part of the chiral Lagrangian gives the additional equation for spin-3/2 fields which gives rise to the inconsistency. This inconsistency can be removed by taking the tetrad to be complex and defining the total Lagrangian which is the sum of the chiral Lagrangian and its complex conjugate. It is possible to establish the right (left)-handed supersymmetry in its total Lagrangian as in the case of the chiral Lagrangian. We also comment on the canonical formulation of the total Lagrangian.

gr-qc↗

arXiv1995

General considerations of matter coupling with the self-dual connection

It has been shown for low-spin fields that the use of only the self-dual part of the connection as basic variable does not lead to extra conditions or inconsistencies. We study whether this is true for more general chiral action. We generalize the chiral gravitational action, and assume that half-integer spin fields are coupled with torsion linearly. The equation for torsion is solved and substituted back into the generalized chiral action, giving four-fermion contact terms. If these contact terms are complex, the imaginary part will give rise to extra conditions for the gravitational and matter field equations. We study the four-fermion contact terms taking spin-1/2 and spin-3/2 fields as examples.

gr-qc↗

arXiv1995

Ashtekar Variables and Matter Coupling

It has been shown for low-spin fields that the use of only the self-dual part of the connection as basic variable does not lead to spurious equations or inconsistencies. We slightly generalize the form of the chiral Lagrangian of half-integer spin fields and express its imaginary part in a simple form. If the imaginary part is non-vanishing, it will lead to spurious equations. As an example, for (Majorana) Rarita-Schwinger fields the equations of motion of the torsion is solved and it is shown that it vanishes owing to the Fierz identity.

gr-qc↗