arXiv subjects
Publications and source records attributed to Motomu Tsuda.
The basic idea and some physical implications of nonlinear supersymmetric general relativity (NLSUSY GR) are discussed, which give new insights into the origin of mass and the mysterious relations between the cosmology and the low energy particle physics, e.g. the spontaneous SUSY breaking scale, the cosmological constant, the (dark) energy density of the universe and the neutrino mass.
We show systematically the relation between a N = 2 nonlinear supersymmetric (NLSUSY) model and a N = 2 SUSY QED theory by means of the superfield formulation in two dimensional spacetime without imposing a priori any special gauge conditions for a gauge superfield.
In the relation between the linear (L) supersymmetry (SUSY) representation and the nonlinear (NL) SUSY representation we discuss the role of the Wess-Zumino gauge. We show in two dimensional spacetime that a spontaneously broken LSUSY theory with mass and Yukawa interaction terms for a minimal off-shell vector supermultiplet is obtained from a general superfield without imposing any special gauge conditions in N = 2 NL/L SUSY relation.
The relation between a N = 2 nonlinear supersymmetric (SUSY) model and a linear SUSY (free) theory for $N = 2$ vector supermultiplet accompanying the spontaneous SUSY breaking is systematically worked out in two-dimensional superfield formulation.
We focus on the superfield formulation for a N = 2 vector supermultiplet in two dimensional spacetime and explicitly show that the Wess-Zumino gauge condition for a N = 2 superfield is compatible with familiar SUSY (plus U(1) gauge) transformations for the vector supermultiplet. N = 2 SUSY invariant mass and Yukawa interaction terms for the vector supermultiplet are also constructed from the superfield explicitly in addition to a free (kinetic) action.
We show explicitly in two dimensional spacetime (d = 2) that the N = 2 Volkov-Akulov model is equivalent to the spontaneously broken linear supersymmetry (LSUSY) interacting gauge theory for N = 2 vector and N = 2 scalar supermultiplets. The local gauge interaction of LSUSY is induced by the specific composite structure of the auxiliary fields and the consequent transformations.
We show explicitly in D = 2 that N = 2 nonlinear supersymmetric (SUSY) Volkov-Akulov model is equivalent to a spontaneously broken N = 2 linear SUSY interacting theory containing the ordinary Yukawa interactions and mass terms, which is renormalizable, by using SUSY invariant relations.
We show that the nonlinear supersymmetric general relativity gives new insights into the origin of mass and elucidates the mysterious relations between the cosmology and the (low energy) particle physics.
We investigate for N = 3 supersymmetry (SUSY) in D = 2 the algebraic relation between the Volkov-Akulov (VA) model of nonlinear (NL) SUSY and a (renormalizable) SO(3) vector supermultiplet of linear (L) SUSY. We derive SUSY and SO(3) invariant relations between component fields of the vector supermultiplet and Nambu-Goldstone (NG) fermions of the VA model at leading orders by using three arbitrary dimensionless parameters which can be recasted as the vacuum expectation values of auxiliary fields in the vector supermultiplet. Two different irreducible representations of SO(3) super-Poincaré symmetry which appear in the same massless state are compatible with each other in the linearization of NL SUSY. The equivalence of a NL SUSY VA action to a free L SUSY action containing the Fayet-Iliopoulos (FI) D term which indicates a spontaneously SUSY breaking is also discussed explicitly according to the SUSY invariant relations.
We focus on a spin-3/2 supersymmetry (SUSY) algebra of Baaklini in D = 3 and explicitly show a nonlinear realization of the SUSY algebra. The unitary representation of the spin-3/2 SUSY algebra is discussed and compared with the ordinary (spin-1/2) SUSY algebra.
We show explicitly that a free Lagrangian expressed in terms of scalar, spinor, vector and Rarita-Schwinger (RS) fields is invariant under linear supersymmetry transformations generated by a global spinor-vector parameter. A (generalized) gauge invariance of the Lagrangian for the RS field is also discussed.
We discuss cosmological implications of nonlinear supersymmetric(NLSUSY) general relativity(GR) of the form of Einstein-Hilbert(EH) action for empty spacetime, where NLSUSY GR is obtained by the geomtrical arguments on new spacetime just inspired by NLSUSY. The new action of NLSUSY GR is unstable and breaks down spontaneously to EH action with Nambu-Goldstone(NG) fermion matter. We show that NLSUSY GR elucidates the physical meanings of the cosmologically important quantities, e.g., the spontaneous SUSY breaking scale, the cosmological constant, the dark energy and the neutrino mass and describe natually the paradigm of the accelerated expansion of the present universe.
We study the unitary representation of supersymmetry (SUSY) algebra based on a spinor-vector generator for both massless and massive cases. A systematic linearization of nonlinear realization for the SUSY algebra is also discussed in the superspace formalism with a spinor-vector Grassmann coordinate.
We focus on a nonlinear supersymmetry (NL SUSY) in curved spacetime introduced in the superon-graviton model (SGM) towards a SUSY composite unified model based on SO(10) super-Poincaré symmetry, and we consider for $N = 1$ SUSY a systematic procedure to linearize the NL SUSY. By introducing modified superspace translations of superspace coordinates and their specific coordinate transformations both depending on a Nambu-Goldstone fermion, we show a homogeneous transformation's law of superfields which is important in the relation between linear (L) and NL SUSY. Furthermore, as a preliminary to find a L supermultiplet which is equivalent to the $N = 1$ NL SUSY SGM multiplet, we discuss on the realization of the modified superspace translations in the construction of a supergravity-like multiplet in the superspace formalism. In particular, we find constraints on a torsion and a Lorentz transformation parameter in the superspace formalism to realize the modified supertranslations.
The Einstein-Hilbert-type action for nonlinear supersymmetric(NLSUSY) general relativity(GR) proposed as the fundamental action for nature is written down explicitly in terms of the fundamental fields, the graviton and the Nambu-Goldstone(NG) fermion(superons). For comparisons the expansion of the action is carried out by using the affine connection formalism and the spin connection formalism. The linearization of NLSUSY GR is considered and carried out explicitly for the N=2 NLSUSY(Volkov-Akulov) model, which reproduce the equivalent renormalizable theory of the gauge vector multiplet of N=2 LSUSY. Some characteristic structures including some hidden symmetries of the gravitational coupling of superons are manifested (in two dimensional space-time) with some details of the calculations. SGM cosmology is discussed briefly.
We discuss further the universality of the Volkov-Akulov (V-A) action of a Nambu-Goldstone (N-G) fermion for the spontaneous breaking of supersymmetry (SUSY). We show general relations between the standard V-A action and nonlinear (NL) SUSY actions including apparently (pathological) higher derivatives of the N-G fermion. Composite fields of the N-G fermions are found, which transform homogeneously under NL SUSY transformations of V-A. Consequently, we obtain NL SUSY invariant constraints which connect our NL SUSY actions with the V-A action. The constraints are explicitly solved and we show examples of the NL SUSY actions which are equivalent to the V-A action.
We investigate for N = 1 supersymmetry (SUSY) the relation between a scalar supermultiplet of linear SUSY and a nonlinear (NL) SUSY model including apparently pathological higher derivaive terms of a Nambu-Goldstone (N-G) fermion besides the Volkov-Akulov (V-A) action. SUSY invariant relations with higher derivative terms of the N-G fermion, which connect the linear and NL SUSY models, are constructed at leading orders by heuristic arguments. We discuss a higher derivative action of the N-G fermion in the NL SUSY model, which apparently includes a (Weyl) ghost field. By using this relation, we also explicitly prove an equivalence between the standard NL SUSY V-A model and our NL SUSY model with the pathological higher derivatives as an example with respect to the universality of NL SUSY actions with the N-G fermion.
We focus on N = 3 chiral supergravity (SUGRA) which is the lowest N theory involving a spin-1/2 field, and derive the Ashtekar's canonical formulation of N = 3 SUGRA starting with the chiral Lagrangian constructed by closely following the standard SUGRA. The polynomiality of constraints in terms of canonical variables and the graded algebraic structure of constraints are discussed in the canonical formulation. In particular, we show the polynomiality of the {\it rescaled} right- and left-handed SUSY constraints by a nonpolynomial factor. And also we show the graded algebraic structure of Osp(3/2) in the constraint algebra by calculating the Poisson brackets of Gauss, SU(2) gauge and right-handed SUSY constraints, although the algebra among only those three types of constraints does not closed.