We give a brief review of our previous works: [1,2]. We discuss two sets of issues. The first has to do with the possibility of getting a non-supersymmetric dS minimum without the addition of anti-D3 branes as in KKLT, and axionic slow-roll inflation, in type II flux compactifications. The second has to do with the "Inverse Problem" [3] and "Fake Superpotentials" [4] for extremal (non)supersymmetric black holes in type II compactifications. We use (orientifold of) a "Swiss Cheese" Calabi-Yau [5] expressed as a degree-18 hypersurface in WCP^4[1,1,1,6,9] in the "large-volume-scenario" limit [6] for the former.
We study the 'Large Volume Scenario' on explicit, new, compact, four-modulus Calabi-Yau manifolds. We pay special attention to the chirality problem pointed out by Blumenhagen, Moster and Plauschinn. Namely, we thoroughly analyze the possibility of generating neutral, non-perturbative superpotentials from Euclidean D3-branes in the presence of chirally intersecting D7-branes. We find that taking proper account of the Freed-Witten anomaly on non-spin cycles and of the Kaehler cone conditions imposes severe constraints on the models. Nevertheless, we are able to create setups where the constrain…
We introduce a new operad, which we call the Swiss-cheese operad. It mixes naturally the little disks and the little intervals operads. The Swiss-cheese operad is related to the configuration spaces of points on the upper half-plane and points on the real line, considered by Kontsevich for the sake of deformation quantization. This relation is similar to the relation between the little disks operad and the configuration spaces of points on the plane. The Swiss-cheese operad may also be regarded as a finite-dimensional model of the moduli space of genus-zero Riemann surfaces appearing in the op…
In this article, we review briefly recent progress made in realizing local(ized around a mobile space-time filling D3-brane in) D3/D7 mu-Split Supersymmetry in (the large volume limit of Type IIB) String Theory (compactified on Swiss-Cheese Calabi-Yau orientifolds) as well as obtaining a 125 GeV (light) Higgs in the same set up. We also discuss obtaining the geometric Kaehler potential (and hence the Ricci-Flat metric) for the Swiss-Cheese Calabi-Yau in the large volume limit using the Donaldson's algorithm and intuition from GLSM-based calculations - we present new results for Swiss-Cheese Ca…
We review progress made over the past couple of years in the field of Swiss Cheese Phenomenology involving a mobile space-time filling D3-brane and stack(s) of fluxed D7-branes wrapping the "big" (as opposed to the "small") divisor in (the orientifold of a) Swiss-Cheese Calabi-Yau. The topics reviewed include reconciliation of large volume cosmology and phenomenology, evaluation of soft supersymmetry breaking parameters, one-loop RG-flow equations' solutions for scalar masses, obtaining fermionic (possibly first two generations' quarks/leptons) mass scales in the O(MeV-GeV)-regime as well as (…
We study an exact swiss-cheese model of the Universe, where inhomogeneous LTB patches are embedded in a flat FLRW background, in order to see how observations of distant sources are affected. We find negligible integrated effect, suppressed by (L/R_{H})^3 (where L is the size of one patch, and R_{H} is the Hubble radius), both perturbatively and non-perturbatively. We disentangle this effect from the Doppler term (which is much larger and has been used recently \cite{BMN} to try to fit the SN curve without dark energy) by making contact with cosmological perturbation theory.
In the context of Type IIB compactified on a large volume Swiss-Cheese orientifold in the presence of a mobile space-time filling D3-brane and stacks of fluxed D7-branes wrapping the "big" divisor Sigma_B of a Swiss-Cheese Calabi Yau in WCP^4 [1,1,1,6,9], we explore various implications of moduli dynamics and discuss their couplings and decay into MSSM (-like) matter fields early in the history of universe to reach thermal equilibrium. Like finite temperature effects in O'KKLT, we observe that the local minimum of zero-temperature effective scalar potential is stable against any finite tempera…
The generalized Swiss - cheese model, consisting of a Lemaître - Tolman (inhomogeneous dust) region matched, by way of a comoving boundary surface, onto a Robertson-Walker background of homogeneous dust, has become a standard construction in modern cosmology. Here we ask if this construction can be made more realistic by introducing some evolution of the boundary surface. The answer we find is no. To maintain a boundary surface using the Darmois - Israel junction conditions, as opposed to the introduction of a surface layer, the boundary must remain exactly comoving. The options are to drop th…
Continuing with the ideas of (section 4 of) [1], after inclusion of perturbative and non-perturbative alpha' corrections to the Kaehler potential and (D1- and D3-) instanton generated superpotential, we show the possibility of slow-roll axionic inflation in the large volume limit of Swiss-Cheese Calabi-Yau orientifold compactifications of type IIB string theory. We also include one- and two-loop corrections to the Kaehler potential but find the same to be subdominant to the (perturbative and non-perturbative) alpha' corrections. The NS-NS axions provide a flat direction for slow-roll inflation…
Building up on our earlier work [1,2], we show the possibility of generating "light" fermion mass scales of MeV-GeV range (possibly related to first two generations of quarks/leptons) as well as eV (possibly related to first two generations of neutrinos) in type IIB string theory compactified on Swiss-Cheese orientifolds in the presence of a mobile space-time filling D3-$brane restricted to (in principle) stacks of fluxed D7-branes wrapping the "big" divisor Σ_B. This part of the paper is an expanded version of the latter half of section 3 of a published short invited review [3] written up by …
In a recent work, it has been proposed that the recent cosmic passage to a cosmic acceleration era is the result of the existence of small anti-gravity sources in each galaxy and clusters of galaxies. In particular, a swiss-cheese cosmology model which relativistically integrates the contribution of all these anti-gravity sources on galactic scale has been constructed assuming the presence of an infrared fixed point for a scale dependent cosmological constant. The derived cosmological expansion provides explanation for both the fine tuning and the coincidence problem. The present work relaxes …
A convincing explanation for the nature of the dark energy and dark matter is still missing. In recent works a RG-improved swiss-cheese cosmology with an evolving cosmological constant dependent on the \sch radius has been proven to be a promising model to explain the observed cosmic acceleration. In this work we extend this model to consider the combined scaling of the Newton constant $G$ and the cosmological constant $Λ$ according to the IR-fixed point hypothesis. We shall show that our model easily generates the observed recent passage from deceleration to acceleration without need of extra…
In this review article, we present a systematic study of large volume type IIB string compactifications that addresses several interesting issues in string cosmology and string phenomenology within a single string compactification scheme. The issues in string cosmology include obtaining a metastable non-supersymmetric dS minimum without adding anti-D3 branes and obtaining slow-roll inflation with the required number of 60 e-foldings along with non-trivial non-Gaussianities and gravitational waves. For studying cosmology and phenomenology within a single string compactification scheme, we provi…
We consider type IIB large volume compactifications involving orientifolds of the Swiss-Cheese Calabi-Yau WCP^4[1; 1; 1; 6; 9] with a single mobile space-time filling D3-brane and stacks of D7-branes wrapping the "big" divisor (as opposed to the "small" divisor usually done in the literature thus far) as well as supporting D7-brane fluxes. After reviewing our proposal of [1] for resolving a long-standing tension between large volume cosmology and phenomenology pertaining to obtaining a 10^12 GeV gravitino in the inflationary era and a TeV gravitino in the present era, and summarizing our resul…
We show that it is possible to realize a "mu-split SUSY" scenario [1] in the context of large volume limit of type IIB compactifications on Swiss-Cheese Calabi-Yau's in the presence of a mobile space-time filling D3-brane and a (stack of) D7-brane(s) wrapping the "big" divisor Sigma_B. For this, we investigate the possibility of getting one Higgs to be light while other to be heavy in addition to a heavy Higgsino mass parameter. Further, we examine the existence of long lived gluino that manifests one of the major consequences of mu-split SUSY scenario, by computing its decay width as well as …
In previous work, we have commenced the task of unpacking the $473,800,776$ reflexive polyhedra by Kreuzer and Skarke into a database of Calabi-Yau threefolds (see http://www.rossealtman.com). In this paper, following a pedagogical introduction, we present a new algorithm to isolate Swiss cheese solutions characterized by "holes," or small 4-cycles, descending from the toric divisors inherent to the original four dimensional reflexive polyhedra. Implementing these methods, we find $2,268$ explicit Swiss cheese manifolds, over half of which have $h^{1,1}=6$. Many of our solutions have multiple …
We consider issues of moduli stabilization and "area codes" for type II flux compactifications, and the "Inverse Problem" and "Fake Superpotentials" for extremal (non)supersymmetric black holes in type II compactifications on (orientifold of) a compact two-parameter Calabi-Yau expressed as a degree-18 hypersurface in WCP^4[1,1,1,6,9] which has multiple singular loci in its moduli space. We argue the existence of extended "area codes" [1] wherein for the same set of large NS-NS and RR fluxes, one can stabilize all the complex structure moduli and the axion-dilaton modulus (to different sets of …
Developing on the ideas of (section 4 of) [1] and [2] and using the formalisms of [3] and [4], after inclusion of perturbative and non-perturbative alpha' corrections to the Kaehler potential and (D1- and D3-) instanton generated superpotential, we show the possibility of getting finite values for the non-linear parameter f_{NL} while looking for non-Gaussianities in type IIB compactifications on orientifolds of the Swiss Cheese Calabi-Yau WCP^4[1,1,1,6,9] in the L(arge) V(olume) S(cenarios) limit. First we show that in the context of multi-field slow-roll inflation, for the Calabi-Yau volume …
We study a brane-world cosmological scenario with local inhomogeneities represented by black holes. The brane is asymmetrically embedded into the bulk. The black strings/cigars penetrating the Friedmann brane generate a Swiss-cheese type structure. This universe forever expands and decelerates, as its general relativistic analogue. The evolution of the cosmological fluid however can proceed along four branches, two allowed to have positive energy density, one of them having the symmetric embedding limit. On this branch a future pressure singularity can arise for either (a) a difference in the …
In type IIB large volume compactifications involving orientifolds of the Swiss-Cheese Calabi-Yau [11169] with a single mobile space-time filling D3-brane and stacks of D7-branes wrapping the "big" divisor (D_5) and supporting D7-brane fluxes, (i) using the toric data and GLSM techniques, we obtain the geometric Kaehler potential for D_5 in terms of genus-two Siegel theta functions; (ii) we show that as the D3-brane moves from a particular embedded non-singular elliptic curve to another one, it is possible to obtain 10^{12}GeV gravitino during the inflationary era as well as a TeV gravitino in …
We propose the natural inflation from the heterotic string theory on "Swiss-Cheese" Calabi-Yau manifold with multiple $U(1)$ magnetic fluxes. Such multiple $U(1)$ magnetic fluxes stabilize the same number of the linear combination of the universal axion and Kähler axions and one of the Kähler axions is identified as the inflaton. This axion decay constant can be determined by the size of one-loop corrections to the gauge kinetic function of the hidden gauge groups, which leads effectively to the trans-Planckian axion decay constant consistent with the WMAP, Planck and/or BICEP2 data. During th…
We systematically analyse globally consistent SU(5) GUT models on intersecting D7-branes in genuine Calabi-Yau orientifolds with O3- and O7-planes. Beyond the well-known tadpole and K-theory cancellation conditions there exist a number of additional subtle but quite restrictive constraints. For the realisation of SU(5) GUTs with gauge symmetry breaking via U(1)_Y flux we present two classes of suitable Calabi-Yau manifolds defined via del Pezzo transitions of the elliptically fibred hypersurface P_{1,1,1,6,9}[18] and of the Quintic P_{1,1,1,1,1}[5], respectively. To define an orientifold proje…
We describe several applications of the recently proposed mass production procedure, where multiple moduli are stabilized in a dS vacuum, in supergravity models inspired by string theory. The construction involves a small downshift of an initial supersymmetric Minkowski minimum to a supersymmetric AdS minimum, and a consequent small uplift to a dS minimum. Our type IIA examples include dS stabilization in a 7-moduli model with $[SL(2, \mathbb{R})]^7$ tree level symmetry, and its simplified version, a 3-moduli STU model. In these models, we use uplifting anti-D6 branes. In type IIB models, we p…
