165 research outputs found

### Anomaly-Mediation and Sequestering from a Higher-Dimensional viewpoint

We study a five-dimensional supergravity model with boundary-localized
visible sector exhibiting anomaly-mediated supersymmetry breaking, in which the
central requirements of sequestering and radius stabilization are achieved
perturbatively. This makes it possible to understand these various mechanisms
in a more integrated and transparent fashion, mostly from the
higher-dimensional viewpoint. Local supersymmetry, in the presence of visible
sector quantum effects, is enforced by the formalism of the five-dimensional
superconformal tensor calculus. The construction results in only mild warping,
which allows a natural supersymmetry-breaking mediation mechanism of (finite)
boundary-to-boundary gravity loops to co-dominate with anomaly-mediation,
thereby solving the latter's tachyonic slepton problem. We make the non-trivial
check that this can occur while dangerous loops of stabilizing fields remain
highly suppressed. Our discussion is a well-controlled starting point for
considering other generalizations of anomaly-mediation, or for string theory
realizations.Comment: 33 pages, typos corrected, added references, version appearing in
JHE

### Asymptotic Symmetries, Holography and Topological Hair

Asymptotic symmetries of AdS$_4$ quantum gravity and gauge theory are derived
by coupling the dual CFT$_3$ to Chern-Simons gauge theory and 3D gravity in a
"probe" large-level limit. The infinite-dimensional symmetries are shown to
arise when one is restricted to boundary subspaces with effectively
two-dimensional geometry. A canonical example of such a restriction occurs
within the 4D subregion described by a Wheeler-DeWitt wavefunctional of AdS$_4$
quantum gravity. An AdS$_4$ analog of Minkowski "super-rotation" asymptotic
symmetry is probed by 3D Einstein gravity, yielding CFT$_2$ structure, via
AdS$_3$ foliation of AdS$_4$ and the AdS$_3$/CFT$_2$ correspondence. The
maximal asymptotic symmetry is however probed by 3D conformal gravity. Both 3D
gravities have Chern-Simons formulation, manifesting their topological
character. Chern-Simons structure is also shown to be emergent in the Poincare
patch of AdS$_4$, as soft/boundary limits of 4D gauge theory, rather than "put
in by hand", with a finite effective Chern-Simons level. Several of the
considerations of asymptotic symmetry structure are found to be simpler for
AdS$_4$ than for Mink$_4$, such as non-zero 4D particle masses, 4D
non-perturbative "hard" effects, and consistency with unitarity. The last of
these, in particular, is greatly simplified, because in some set-ups the time
dimension is explicitly shared by each level of description: Lorentzian
AdS$_4$, CFT$_3$ and CFT$_2$. The CFT$_2$ structure clarifies the sense in
which the infinite asymptotic charges constitute a useful form of "hair" for
black holes and other complex 4D states. An AdS$_4$ (holographic) "shadow"
analog of Minkowski "memory" effects is derived. Lessons from AdS$_4$ provide
hints for better understanding Minkowski asymptotic symmetries, the 3D
structure of its soft limits, and Minkowski holography.Comment: typos corrected, references added, discussions of boundary conditions
corrected and clarifie

### Unfolding Particle Physics Hierarchies with Supersymmetry and Extra Dimensions

This is a written version of lectures delivered at TASI 2022 ``Ten Years
After the Higgs Discovery: Particle Physics Now and Future''. Mechanisms and
symmetries beyond the Standard Model (BSM) are presented capable of elegantly
and robustly generating the striking hierarchies we observe in particle
physics. They are shown to be among the central archetypes of quantum effective
field theory and to strongly resonate with the tight structure and
phenomenology of the Standard Model itself, allowing one to motivate, develop
and test a worthy successor. The (Little) Hiearchy Problem is discussed within
this context. The lectures culminate in specific BSM case-studies,
gaugino-mediated (dynamical) supersymmetry breaking to generate the weak/Planck
hierarchy, and (in less detail) extra-dimensional wavefunction overlaps to
generate flavor hierarchies.Comment: 62 pages, 24 figures, TASI 2022 lectures, new references added in [3]
and [20

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