14678443
Towards vacuum superstring field theory: The supersliver
We extend some aspects of vacuum string field theory to superstring field theory in Berkovits’ formulation, and we study the star algebra in the fermionic matter sector. After clarifying the structure of the interaction vertex in the operator formalism of Gross and Jevicki, we provide an algebraic construction of the supersliver state in terms of infinite–dimensional matrices. This state is an idempotent string field and solves the matter part of the equation of motion of superstring field theory with a pure ghost BRST operator. We determine the spectrum of eigenvalues and eigenvectors of the infinite–dimensional matrices of Neumann coefficients in the fermionic matter sector. We then analyze coherent states based on the supersliver and use them in order to construct higher–rank projector solutions, as well as to construct closed subalgebras of the star algebra in the fermionic matter sector. Finally, we show that the geometric supersliver is a solution to the superstring field theory equations of motion,...
16528220
Donaldson Invariants of Product Ruled Surfaces¶and Two-Dimensional Gauge Theories
Abstract: Using the u-plane integral of Moore and Witten, we derive a simple expression for the Donaldson invariants of product ruled surfaces Σg×S2, where Σg is a Riemann surface of genus g. This expression generalizes a theorem of Morgan and Szabó for g=1 to any genus g. We give two applications of our results: (1) We derive Thaddeus' formulae for the intersection pairings on the moduli space of rank two stable bundles over a Riemann surface. (2) We derive the eigenvalue spectrum of the Fukaya–Floer cohomology of Σg×S1.
119634813
Instanton Effects and Quantum Spectral Curves
We study a spectral problem associated to the quantization of a spectral curve arising in local mirror symmetry. The perturbative WKB quantization condition is determined by the quantum periods, or equivalently by the refined topological string in the Nekrasov–Shatashvili (NS) limit. We show that the information encoded in the quantum periods is radically insufficient to determine the spectrum: there is an infinite series of instanton corrections, which are non-perturbative in $${\hbar}$$ħ, and lead to an exact WKB quantization condition. Moreover, we conjecture the precise form of the instanton corrections: they are determined by the standard or unrefined topological string free energy, and we test our conjecture successfully against numerical calculations of the spectrum. This suggests that the non-perturbative sector of the NS refined topological string contains information about the standard topological string. As an application of the WKB quantization condition, we explain some recent observations relating membrane instanton corrections in ABJM theory to the refined topological string.
15868022
Donaldson Invariants for Non-Simply Connected Manifolds
Abstract:We study Coulomb branch (“u-plane”) integrals for supersymmetric SU(2),SO(3) Yang–Mills theory on 4-manifolds X of b1(X)>0, b2+(X)= 1. Using wall-crossing arguments we derive expressions for the Donaldson invariants for manifolds with b1(X)>0, b2+(X)>0. Explicit expressions for , where Fg is a Riemann surface of genus g are obtained using Kronecker's double series identity. The result might be useful in future studies of quantum cohomology.
6749775
Topological Open Strings on Orbifolds
We use the remodeling approach to the B-model topological string in terms of recursion relations to study open string amplitudes at orbifold points. To this end, we clarify modular properties of the open amplitudes and rewrite them in a form that makes their transformation properties under the modular group manifest. We exemplify this procedure for the $${{\mathbb C}^3/{\mathbb Z}_3}$$ orbifold point of local $${{\mathbb P}^2}$$, where we present results for topological string amplitudes for genus zero and up to three holes, and for the one-holed torus. These amplitudes can be understood as generating functions for either open orbifold Gromov–Witten invariants of $${{\mathbb C}^3/{\mathbb Z}_3}$$, or correlation functions in the orbifold CFT involving insertions of both bulk and boundary operators.
13035866
Topological open string amplitudes on orientifolds
We study topological open string amplitudes on orientifolds without fixed planes. We determine the contributions of the untwisted and twisted sectors as well as the BPS structure of the amplitudes. We illustrate our general results in various examples involving D-branes in toric orientifolds. We perform the computations by using both the topological vertex and unoriented localization. We also present an application of our results to the BPS structure of the coloured Kauffman polynomial of knots.
117928153
Maximum Likelihood Signal Extraction Method Applied to 3.4 years of CoGeNT Data
CoGeNT has taken data for over 3 years, with 1136 live days of data accumulated as of April 23, 2013. We report on the results of a maximum likelihood analysis to extract any possible dark matter signal present in the collected data. The maximum likelihood signal extraction uses 2-dimensional probability density functions (PDFs) to characterize the anticipated variations in dark matter interaction rates for given observable nuclear recoil energies during differing periods of the Earth's annual orbit around the Sun. Cosmogenic and primordial radioactivity backgrounds are characterized by their energy signatures and in some cases decay half-lives. A third parameterizing variable -- pulse rise-time -- is added to the likelihood analysis to characterize slow rising pulses described in prior analyses. The contribution to each event category is analyzed for various dark matter signal hypotheses including a dark matter standard halo model and a case with free oscillation parameters (i.e., amplitude, period, and phase). The best-fit dark matter signal is in close proximity to previously reported results. We find that the significance of the extracted dark matter signal remains well below evidentiary at 1.7 $\sigma$.
116949545
A search for bremsstrahlung solar axions using the Majorana Low-background BEGe detector at Kimballton (MALBEK)
(95% CL) is placedon the direct coupling of DFSZ model axions to electrons. The prospects for the sensitivity ofthe Majorana Demonstrator array of point-contact germanium detectors to solar axions arediscussed in the context of the model-independent annual modulation due to the seasonal variationof the earth-sun distance.
9512698
Astroparticle physics with a customized low-background Broad Energy Germanium detector
We have found that modified Broad Energy Ge detectors produced by CANBERRA have several promising features, including large mass, low electronic noise, and excellent pulse-shape analysis capabilities. Modified BEGe detectors obtain these capabilities due to their low-capacitance “point-contact” electrode configuration. Modified BEGes are also the only point-contact design fabricated on a commercial basis. We have deployed a modified BEGe, named “MALBEK” in a low-background cryostat and shield in the Kimballton Underground Research Facility, located in Ripplemead, Virginia at a depth of 1450 meters water equivalent. We will focus on detector characteristics, data acquisition, and analysis techniques used with MALBEK.
116193420
Comments on arXiv:0902.4693v1 'Search for Axions with the CDMS Experiment'
We offer a few remarks that should help clarify the relative sensitivity of CoGeNT, CDMS and DAMA to dark pseudoscalars. An alternative dark matter origin for the DAMA modulation is briefly mentioned within this context.
119108760
CoGeNT: A Search for Low-Mass Dark Matter using p-type Point Contact Germanium Detectors
CoGeNT employs $p$-type point-contact (PPC) germanium detectors to search for weakly interacting massive particles (WIMPs). By virtue of its low-energy threshold and ability to reject surface backgrounds, this type of device allows an emphasis on low-mass dark matter candidates (${m}_{\ensuremath{\chi}}\ensuremath{\sim}10\text{ }\text{ }\mathrm{GeV}/{c}^{2}$). We report on the characteristics of the PPC detector presently taking data at the Soudan Underground Laboratory, elaborating on aspects of shielding, data acquisition, instrumental stability, data analysis, and background estimation. A detailed background model is used to investigate the low-energy excess of events previously reported and to assess the possibility of temporal modulations in the low-energy event rate. Extensive simulations of all presently known backgrounds do not provide a viable background explanation for the excess of low-energy events in the CoGeNT data or the previously observed temporal variation in the event rate. Also reported for the first time is a determination of the surface (slow pulse rise time) event contamination in the data as a function of energy. We conclude that the CoGeNT detector technology is well suited to search for the annual modulation signature expected from dark matter particle interactions in the region of WIMP mass and coupling favored by the DAMA/LIBRA results.