We describe a simple model of Dark Matter, which explains the PAMELA/ATIC excesses while being consistent with all present constraints. The DAMA annual modulation signal can also be explained for some values parameters. consists Sector containing weakly coupled broken U(1) gauge symmetry, under only Matter state and leptons are charged.

We propose a new solution to the supersymmetric flavor problem without flavor-blind mediation. Our proposal is enforce continuous or suitably large discrete R-symmetry on weak scale supersymmetry, so that Majorana gaugino masses, trilinear A-terms, and mu-term are forbidden. find replacing MSSM with an R-symmetric model allows order one flavor-violating soft even for squarks of few hundred GeV. The minimal contains Dirac masses Higgsino no left-right mixing in squark slepton sector. TeV...

All generic, calculable models of dynamical supersymmetry breaking have a spontaneously broken R-symmetry and therefore contain an R-axion. We showthat the axion is massive in any model which cosmological constant fine-tuned to zero through explicit R-symmetry-breaking c constant. In visible-sector models, mass 100 MeV range thus evades astrophysical bounds. nonrenormalizable hidden-sector order weak scale can dangerous consequences similar those already present from other fields....

We prove that global anomaly cancellation requires more than one generation of quarks and leptons, provided the standard model fields propagate in two universal extra dimensions. Furthermore, if fermions different generations have same gauge charges chiralities, then implies there must be three generations.

We study four dimensional $SU(2)$ Yang-Mills theory with two massless adjoint Weyl fermions. When compactified on a spatial circle of size $L$ much smaller than the strong-coupling scale, this can be solved by weak-coupling nonperturbative semiclassical methods. possible realizations symmetries in $\mathbb R^4$ limit and find that all continuous discrete $0$-form $1$-form 't Hooft anomaly matching conditions are saturated symmetry realization spectrum identical to found small-$L$ limit, only...

A bstract We study the domain walls in hot 4-D SU( N ) super Yang-Mills theory and QCD(adj), with n f Weyl flavors. find that k -wall worldvolume is 2-D QCD gauge group − × U(1) Dirac fermions charged under transforming bi-fundamental representation of nonabelian factors. show DW has a 1-form ℤ (1) center symmetry 0-form $$ {\mathbb{Z}}_{2N{n}_f}^{d\chi } <mml:math...

We examine the stability of mass hierarchy in hidden-sector supergravity theories. show that a quadratically divergent tadpole can appear at two loops, even minimal theories, provided theory has gauge- and global-symmetry singlet with renormalizable couplings to visible fields. This destabilize hierarchy. also find two-loop contribution field-dependent vacuum energy. result casts doubt on efficacy "LHC mechanism" for controlling quadratic divergences. carry out calculation manifestly...

Nonrenormalizable couplings in supergravity-coupled supersymmetric theories can give rise to power-law divergences that destabilize the weak-scale hierarchy. For case of standard-model gauge group, problem arise with SU(3)\ifmmode\times\else\texttimes\fi{}SU(2)\ifmmode\times\else\texttimes\fi{}U(1) gauge-singlet chiral superfluids. The minimal standard model is free from such destabilizing divergences.

We study four-dimensional N=2 supersymmetric pure-gauge (Seiberg-Witten) theory and its N=1 mass perturbation by using compactification S**1 x R**3. It is well known that on R**4 (or at large S**1) the perturbed realizes confinement through monopole or dyon condensation. At small S**1, we demonstrate induced a generalization of Polyakov's three-dimensional instanton mechanism to locally - magnetic bion which also applies class nonsupersymmetric theories. Using large- vs. small-L Poisson...

We study the phase structure of $$ \mathcal{N} = 1 supersymmetric Yang-Mills theory on ℝ3 × \mathbb{S} 1, with massive gauginos, periodic around Sp(2N) (N ≥ 2), Spin(N) 5), G 2, F 4, E 6, 7, 8 gauge groups. As gaugino mass m is increased, S1 size and strong coupling scale fixed, we find a first-order transition both for theories without center. This semiclassically calculable driven, as in SU(N) 2 [1, 2], by competition between monopole-instantons exotic topological "molecules" — "neutral"...

We study strings between static quarks in QCD with ${n}_{f}$ adjoint fermions, including $\mathcal{N}=1$ supersymmetric Yang-Mills (SYM), the calculable regime on ${\mathbb{R}}^{3}\ifmmode\times\else\texttimes\fi{}{\mathbb{S}}_{L}^{1}$, which shares many features XY-spin model. find that they have qualitatively new not previously known. The difference from other realizations of Abelian confinement is due to composite nature magnetic bions, whose Dirac quantum fundamental two, and unbroken...

QCD-like theories can be engineered to remain in a confined phase when compactified on an arbitrarily small circle, where their features may studied quantitatively controlled fashion. Previous work has elucidated the generation of nonperturbative mass gap and spontaneous breaking chiral symmetry this regime. Here, we study rich spectrum hadronic states, including glueball, meson, baryon resonances. We find exponentially growing Hagedorn density as well emergence energy scales given by...

A bstract We compute the gaugino condensates, $$ \left\langle {\Pi}_{i=1}^k\textrm{tr}\left(\uplambda \uplambda \right)\left({x}_i\right)\right\rangle <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mfenced> <mml:mrow> <mml:msubsup> <mml:mi>Π</mml:mi> <mml:mi>i</mml:mi> <mml:mo>=</mml:mo> <mml:mn>1</mml:mn> </mml:mrow> <mml:mi>k</mml:mi> </mml:msubsup> <mml:mi>tr</mml:mi> <mml:mi>λλ</mml:mi> </mml:mfenced> <mml:msub> <mml:mi>x</mml:mi> </mml:msub> </mml:math> for 1 ≤ k N − 1,...

A bstract We embed the multi-fractional instantons of SU( N ) gauge theories on $$ {\mathbbm{T}}^4 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msup> <mml:mi>T</mml:mi> <mml:mn>4</mml:mn> </mml:msup> </mml:math> with ’t Hooft twisted boundary conditions into U( bundles and use Nahm transform to study corresponding configurations dual {\hat{\mathbbm{T}}}^4 <mml:mover> <mml:mo>̂</mml:mo> </mml:mover> . first show that fractional topological charge Q=\frac{r}{N},r\in...

We consider the generation of Fayet-Iliopoulos terms at one string loop in some recently found N = 1 open orbifolds with anomalous U(1) factors non-vanishing trace charge. Low-energy field theory arguments lead to expect a one-loop quadratically divergent term. show that term is not generated, due cancellation between contributions world-sheets different topology. The vanishing compactifications related twisted Ramond-Ramond tadpoles.

We study the solutions of Einstein equations in (d+2)-dimensions, describing parallel p-branes (p=d-1) a space with two transverse dimensions positive gaussian curvature. These generalize Deser and Jackiw point particle sources (2+1)-dimensional gravity cosmological constant. Determination metric is reduced to finding roots simple algebraic equation. also determine nontrivial "warp factors" at positions branes. discuss possible role these importance context large extra scenario.

We show that supersymmetry breaking in a class of theories with SU$(N)\ifmmode\times\else\texttimes\fi{}\mathrm{SU}(N\ensuremath{-}2)$ gauge symmetry can be studied calculable $\ensuremath{\sigma}$ model. use the model to supersymmetry-breaking vacuum these leaves large subgroup flavor symmetries intact, and calculate masses low-lying states. By embedding standard groups unbroken group we construct models which is communicated by both gravitational interactions. One distinguishing feature...

A bstract We study the discrete chiral- and center-symmetry ’t Hooft anomaly matching in charge- q two-dimensional Schwinger model. show that algebra of symmetry operators involves a central extension, implying existence vacua, chiral center symmetries are spontaneously broken. then argue an axial version = 2 model appears worldvolume theory on domain walls between breaking vacua high-temperature SU(2) $$ \mathcal{N}=1 <mml:math...