Conveners
Parallel V: Gravity/Cosmology
- Lan Nguyen (Hanoi National University of Education)
Parallel V: Inflation and alternatives
- Gary Shiu (University of Wisconsin & HKUST)
Parallel V: Strings/GUT
- Kameshwar C Wali (Syracuse University)
Parallel V: Strings/GUT
- Xerxes Tata (University of Hawaii)
We study the cosmological history of the classical conformal B−L gauge extension of the standard model, in which the physical scales are generated via the Coleman-Weinberg-type symmetry breaking. Especially, we consider the thermal phase transition of the U(1)B−L symmetry in the early universe and resulting gravitational-wave production. Due to the classical conformal invariance, the phase...
To determine bubble nucleation rates precisely, we need to evaluate functional determinants around the bounce background. In gauge theories, there appears a mixing between the would-be NG boson and the gauge boson, and it becomes quite difficult to see the gauge dependence of the functional determinant. Though the gauge independence of the effective action is proven by Nielsen at all orders,...
It is known that chiral primordial gravitational waves (GWs) are provided due to the strong interaction of gauge fields to axions during inflation. Interestingly, in the case of non-Abelian gauge fields, they can produce chiral GWs at linear level. In this talk, we explain the mechanism of generating such chiral primordial GWs and discuss their detectability in future observations.
We investigates how nontrivial topology affects the entanglement dynamics between a detector and a quantum field and between two detectors mediated by a quantum field. Nontrivial topology refers to both that of the \textit{base space}
and that of the \textit{bundle}. Using a derivative-coupling Unruh-DeWitt-like detector model interacting with a quantum scalar field in an Einstein...
We are going to calculate the flow of the angular momentum and flux of the Hawking radiation in the rotating regular black hole with the time-delay proposed in arXiv:1510.08828, based on the anomaly cancellation. We first try to reduce the field theories to the infinite two-dimensional massless free models in which the anomaly cancellation method is possible, in the three metrics in...
Inflation due to a non-minimally coupled scalar field is in good agreement with the observed value of spectral index and constraints on the tensor-to-scalar ratio. Here we explore the possibility that non-minimally coupled inflation represents the late stage of a Universe which emerges from an early contracting era. We present a model in which the Universe smoothly transitions from an...
In this talk, I will report on my [latest work][1] together with Tsutomu Yanagida on an interesting possibility to unify the dynamics of spontaneous supersymmetry breaking and cosmic inflation. Our model is based on strong gauge dynamics, explains the high supersymmetry breaking scale, and also provides an answer to the question "why is there such a thing as cosmic inflation in the first...
After the release of the PLANCK data, it is evident that inflationary paradigm has stood the test of time. Even though, it is difficult to realise inflationary paradigm in a particle physics model as the present observations have ruled out the simplest quartic and quadratic inflationary potentials, which generically arise in particle physics. We would show that such simplest inflationary...
A reformulation of inflationary model analyses appeared recently, in which inflationary observables are determined by the structure of a pole in the inflaton kinetic term rather than the shape of the inflaton potential.
This is called pole inflation, and it is a generalization of $\alpha$-attractors and $\zeta$-attractors.
The predicted values of inflationary observables are universal in the...
We revisit the compatibility between the chaotic inflation, which provides a natural solution to the initial condition problem, and the metastable electroweak vacuum, which is suggested by the results of LHC and the current mass measurements of top quark and Higgs boson. It is known that the chaotic inflation poses a threat to the stability of the electroweak vacuum because it easily generates...
We will present main results of our recent study on higher dimensional scenarios of a ghost-free nonlinear massive gravity proposed by de Rham, Gabadadze, and Tolley (dRGT). In particular, a useful method, which is based on the Cayley-Hamilton theorem, to construct higher dimensional massive graviton terms will be presented. The constant-like behavior of massive graviton terms of...
The essential point is that the mass of the lightest right-handed neutrino can be enhanced in the model because it has a lot of mass terms whose mass parameters are predicted to be the same order of magnitude which is smaller than $10^8$ GeV. We show that O(10) enhancement for the lightest right-handed neutrino mass is sufficient for the observed baryon asymmetry. Note that such mass...
Magnetic fluxes in extra dimensional space can be an origin of the flavor structure of the standard model. In particular, in higher-dimensional supersymmetric Yang-Mills (SYM) theories compactified on magnetized orbifolds, several MSSM-like models were constructed successfully.
In this work, we derive dynamical supersymmetry breaking models from a single SYM theory compactified on magnetized...
In this talk, we show the concrete embeddings of the standard model gauge groups into SO(32) gauge group in terms of the multiple U(1) fluxes. The correct matter contents of the standard model are then derived from the adjoint and vector representations of SO(12) given by the subgroup of SO(32).
Since the number of generations corresponds to the number of U(1) fluxes, we search for the...
We propose and study a holographic dual of the type IIB superstring theory of AdS_5xS^5 in terms of the N=4 superconformal Yang-Mills theory on dS_4. We review the bulk to boundary formalism to evaluate the boundary correlation functions. Then we present several non-local observables related to heavy quarks in the dual theory on dS_4.
Recently an SO(11) gauge-Higgs grand unified theory (GHGUT) in 5D Randall-Sundrum warped space was proposed in PTEP(2015)111B01(arXiv:1504.03817). In this framework, the 4D SM bosons and fermions are naturally realized by the SO(11) bulk gauge boson and SO(11) spinor bulk fermions, respectively. GHGUT leads to gauge coupling unification, so it is inevitable to discuss the renormalization group...
From compactification of E8xE8 heterotic string, I attempt to construct an extended GUT where families are unified. There appears an anti-SU(7) GUT group from which weak CP is calculated under the assumption of only one CP phase in the theory.
Quantum field theory on curved space-times is a very powerful framework for the study of quantum phenomena in situations where gravitation itself can be treated classically. Of special interest is the study of interacting quantum fields in de Sitter space-time, where corrections computed using the standard perturbative expansion are plagued by contributions that secularly grow with time...
The Dirac-Born-Infeld (DBI) action play important roles in the context of string theory. In the string theory, an effective action of D-brane is described by a DBI-type action, which consists of Maxwell terms? as well as the ones of scalar fields in general. From a phenomenological and theoretical viewpoint, the embedding of the DBI action into supersymmetry (SUSY) or supergravity (SUGRA) is...
The coupling of gravity to chiral quark-leptons is investigated in the Discretized Kaluza-Klein theory with a new Dirac operator and a new wedge product. It is reduced to the couplings of chiral quark-spinors to the ordinary gravity and the gauge fields together with new interaction terms.
We consider gravitational wave production by bubble collisions during a cosmological first-order phase transition. In the literature, such spectra have been estimated by simulating the bubble dynamics, under so-called thin-wall and envelope approximations in a flat background metric. How- ever, we show that, within these assumptions, the gravitational wave spectrum can be estimated in an...
The accelerated expansion of the universe is strongly manifested
after the discovery of unexpected reduction in the detected energy
fluxes coming from SNe Ia. Other observational data
like CMBR, LSS and galaxy redshift surveys also
provide evidences in this favor. These observations propose a
mysterious form of force, referred as dark energy (DE), which takes
part in the expansion...
