We explore a higher-dimensional universe that is a product of Minkowski space and the nonorientable Klein bottle. The topology explicitly breaks important symmetries, such as translational invariance and (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mn>5</mn><mo>+</mo><mn>1</mn></mrow></math>)-dimensional <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>C</mi><mi>P</mi></math> invariance. Somewhat surprisingly, the (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mn>3</mn><mo>+</mo><mn>1</mn></mrow></math>)-dimensional <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>c</mi><mi>p</mi></math> of the Minkowski space can also be broken by the Klein bottle, both explicitly and in the presence of a brane. The topology enforces a background of fermion correlations that amounts to a condensate wall localized in the Klein bottle. The wall acts as an order parameter for the broken symmetries. If a brane passes through the wall, brane fermions that couple to the condensate are produced as quantified by the Bogoliubov coefficients for a time-dependent mass. The scenario meets the conditions, including <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>c</mi><mi>p</mi></math> violation, to potentially generate the matter-antimatter asymmetry of the universe.

United States

Brian Greene

Daniel Kabat

Janna Levin

Massimo Porrati

Klein bottle cosmology

In higher-dimensional theories, we often assume that the extra dimensions form an orientable space, perhaps with singularities. However, many physical theories are well defined on nonorientable spaces, and many spaces are not orientable, so it is reasonable to explore what happens if the assumption of orientability is relaxed. Here we consider the simplest example of free 6D theories compactified on a flat Klein bottle. We focus on a Dirac fermion in 6D, with boundary conditions that define <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>pin</mi><mo>+</mo></msup></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>pin</mi><mo>−</mo></msup></math> structures. Translation invariance is broken by the boundary conditions, which leads to sharp features localized near the parity walls (fixed points of the reflection used to construct the Klein bottle). For a scalar field, there is a position-dependent energy density, peaked near the parity walls. A Dirac fermion can lead to breaking of parity, charge conjugation, and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>C</mi><mi>P</mi></math> in <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>3</mn><mo>+</mo><mn>1</mn></math> dimensions. Order parameters for this breaking are provided by the vacuum expectation values of certain fermion bilinears, again peaked near the parity walls. As one potential application, these results suggest mechanisms for <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>C</mi><mi>P</mi></math> violation and baryogenesis, enabled by compactification on a Klein bottle.

Compactification without orientation, or a topological scenario for <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>C</mi><mi>P</mi></math> violation

We study 3D anti–de Sitter minimal massive gravity in two regimes: a) at the chiral limit where one of the boundary Brown-Henneaux central charges vanishes and two modes become null and b) in the regime where one of the two charges is much larger than the other. At the chiral point, we go beyond the known free-theory analysis to prove that these modes decouple completely also in the full MMG Lagrangian and field equations. We also use the full action to ascertain if the interacting theory becomes infinitely strongly coupled in the neighborhood of the chiral limit, where the theory is not unitary. We show that this is not the case at tree level but that a strong coupling pathology appears in loops, starting at a loop level determined by the number of external legs in the bulk Feynman diagrams. Finally, we show that there is no strong coupling problem in the second regime where, instead, the two boundary fields and the field propagating in the bulk decouple from one another.

Xilin Sheng

Chiral limit of fully nonlinear minimal massive gravity

A model of supergravity inflation we recently proposed can produce slow roll inflation and a realistic spectrum of particles even without F-term supersymmetry breaking. Supersymmetry is broken only by a D-term induced by a recently discovered new type of Fayet-Iliopoulos (FI) term. Almost all supersymmetric partners of the standard model fields can get masses as high as the inflationary Hubble scale. The exception is gauginos, for which the vanishing of F-terms implies an exact cancellation that keeps their masses exactly zero. To cure this problem without spoiling the simplicity of our model we introduce a new term that further enlarges the space of supergravity effective actions. It is an F-term that, similarly to the new FI term, becomes singular in the supersymmetric limit. We show that this term can produce large gaugino masses without altering the spectrum of other states and without lowering the cutoff of the effecive theory.

Japan

South Korea

Hun Jang

Supermassive gauginos in supergravity inflation with high-scale SUSY breaking

We describe and solve three puzzles arising in covariant and supertranslation-invariant formulas for the flux of angular momentum and other Lorentz charges in asymptotically flat spacetimes: (i) Supertranslation invariance and covariance imply invariance under spacetime translations; (ii) the flux depends on redundant auxiliary degrees of freedom that cannot be set to zero in all Lorentz frames without breaking Lorentz covariance; (iii) supertranslation-invariant Lorentz charges do not generate the transformations of the Bondi mass aspect implied by the isometries of the asymptotic metric. In this Letter, we solve the first two puzzles by presenting covariant formulas that unambiguously determine the auxiliary degrees of freedom and clarify the last puzzle by explaining the different roles played by covariant and canonical charges. Our construction makes explicit the choice of reference frame underpinning seemingly unambiguous results presented in the current literature.

Reza Javadinezhad

Three Puzzles with Covariance and Supertranslation Invariance of Angular Momentum Flux and Their Solutions

A recently proposed effective action for the trace anomaly describes a tensor-scalar theory that is weakly coupled up to a certain high energy scale, where it becomes strongly interacting. Its ultraviolet completion is obtained by coupling to gravity a quantum field theory in which conformal invariance is spontaneously broken. In this paper, we show that if the field theory that gives rise to the trace anomaly is a large <math><msub><mi>N</mi><mi>c</mi></msub></math> conformal field theory, then the trace anomaly action has a completion above the strong scale in a holographic Randall-Sundrum two-brane theory, with the radion as a low energy remnant of the spontaneously broken conformal symmetry. Furthermore, we note that the subleading <math><msub><mi>N</mi><mi>c</mi></msub></math> terms can be derived by adding localized fields to the UV brane, so that the theory remains weakly coupled. The subleading terms are also obtained by introducing the Weyl squared terms in the 5D bulk. These, however, exhibit strongly coupled behavior at the respective sub-Planckian energy scales.

Gregory Gabadadze

United Kingdom

Holography for the trace anomaly action

We study solvable deformations of two-dimensional quantum field theories driven by a bilinear operator constructed from a pair of conserved U(1) currents J a . We propose a quantum formulation of these deformations, based on the gauging of the corresponding symmetries in a path integral. This formalism leads to an exact dressing of the S-matrix of the system, similarly as what happens in the case of a <math> <mi>T</mi> <mover> <mi>T</mi> <mo>¯</mo> </mover> </math> $$ \textrm{T}\overline{\textrm{T}} $$ deformation. For conformal theories the deformations under study are expected to be exactly marginal. Still, a peculiar situation might arise when the conserved currents J a are not well-defined local operators in the original theory. A simple example of this kind of system is provided by rotation currents in a theory of multiple free, massless, non-compact bosons. We verify that, somewhat unexpectedly, such a theory is indeed still conformal after deformation and that it coincides with a TsT transformation of the original system. We then extend our formalism to the case in which the conserved currents are non-Abelian and point out its connection with Deformed T-dual Models and homogeneous Yang-Baxter deformations. In this case as well the deformation is based on a gauging of the symmetries involved and it turns out to be non-trivial only if the symmetry group admits a non-trivial central extension. Finally we apply what we learned by relating the <math> <mi>T</mi> <mover> <mi>T</mi> <mo>¯</mo> </mover> </math> $$ \textrm{T}\overline{\textrm{T}} $$ deformation to the central extension of the two-dimensional Poincaré algebra.

Sergei Dubovsky

Stefano Negro

Topological gauging and double current deformations

A new supergravity D-term, not associated to gauged R-symmetry, was recently discovered and used to construct new supergravity models. In this paper we use a generalization of the new D-term that we used in previous works, to construct a supergravity model of slow-roll inflation with the observable sector of the minimal supersymmetric standard model. Supersymmetry is broken at a high scale in the hidden sector and communicated to the observable sector by gravity mediation. The new D-term contains free parameters that can give large masses to scalar superpartners of quarks and leptons and to the higgsinos while holding the masses of observed particles fixed. Gauginos receive a mass from a noncanonical kinetic term for the vector supermultiplets. We also present a simple argument proving in full generality that the cutoff <math><mi>Λ</mi></math> of effective theories containing new D-terms can never exceed the supersymmetry breaking scale. In our theory, the relation between D-term and the Hubble constant during inflation also implies the universal relation <math><mrow><mi>Λ</mi><mo>≲</mo><msqrt><mrow><mi>H</mi><msub><mrow><mi>M</mi></mrow><mrow><mi>Pl</mi></mrow></msub></mrow></msqrt></mrow></math>.

Realization of slow-roll inflation and the MSSM in supergravity theories with new Fayet-Iliopoulos terms

We present an explicit formula for Lorentz boosts and rotations that commute with BMS supertranslations in asymptotically flat spacetimes. Key to the construction is the use of infrared regularizations and of a unitary transformation that makes observables commute with the soft degrees of freedom. We explicitly verify that our charges satisfy the Lorentz algebra and we check that they are consistent with expectations by evaluating them on the supertranslated Minkowski space and on the boosted Kerr black hole.

Israel

Uri Kol

Supertranslation-invariant dressed Lorentz charges

We explicitly compute the component action of certain recently discovered new <math> <mi>N</mi> </math> $$ \mathcal{N} $$ = 1 supergravity actions which enlarge the space of scalar potentials allowed by supersymmetry and also contain fermionic interaction terms that become singular when supersymmetry is unbroken. They are the “Liberated Supergravity” introduced by Farakos, Kehagias and Riotto, and supergravities with a new Kähler-invariant Fayet-Iliopoulos term proposed by Antoniadis, Chatrabhuti, Isono, and Knoops. This paper is complementary to our previous papers [Phys. Rev. D 103 (2021) 025008 and 105006], in which new constraints on the coupling constants of those new theories were found. In this paper we spell out many details that were left out of our previous papers.

Component actions of liberated <math> <mi>N</mi> </math> $$ \mathcal{N} $$ = 1 supergravity and new Fayet-Iliopoulos terms in superconformal tensor calculus