Hierarchical Universe Research Articles

Unified Field Theory and the Hierarchical Universe

Everything from the smallest particle to the grand universe is constructed by Torque Grids. The grand structure of the universe is made up of infinite hierarchical Torque Grids; this theory falsifies Big Bang Theory (BBT) and Black Hole Theory. A Torque Grid is 10-25 times smaller than an atom, and our universal Torque Grid size is 4.98 * 1026 m. The Universe is timeless. The configuration of Spiral Arm Galaxy can also be explained by Unified Field Theory.

Effects on galaxy evolution: pair interactions versus environment

In a hierarchical universe, mergers may be an important mechanism not only in increasing the mass of galaxies but also in driving the color and morphological evolution of galaxies. We use a large sample of ~1000 simulated galaxies of stellar mass greater than 10^9.6 solar masses (for ~4800 observations at multiple redshifts) from a high-res (0.46 h^{-1} kpc) cosmological simulation to determine under what circumstances being a member of a pair influences galaxy properties at z <= 0.2. We identify gravitationally bound pairs, and find a relative fraction of blue-blue, red-red, and blue-red pairs that agrees with observations (Lin et al. 2010). Pairs tend to avoid the extreme environments of clusters and void centres. While pairs in groups can include galaxies that are both blue, both red, or one of each color, in the field it is rare for pair galaxies to both be red. We find that physically bound pairs closer than 250 h^{-1} kpc tend to have higher sSFRs than the galaxy population as a whole. However, the sSFR of a bound galaxy relative to galaxies in a comparable local density environment (determined by the distance to the fifth nearest neighbor, rho_5), differs depending on the local density. In regions of high rho_5 the bound population has a higher fraction of star-forming (bluer) galaxies, whereas there is very little difference between bound and unbound galaxies in low rho_5 regions. This effect on the star-forming fraction may be driven by the higher fraction of bound HI-rich galaxies compared to unbound galaxies, particularly at high local densities. It appears that being in a pair has an incremental, but not overwhelming, effect on the star formation rate of the paired galaxies, compared to the more pronounced trend where galaxies overall have low sSFR (are red) in clusters and higher sSFR (blue) at the centre of voids. This trend depends most strongly on rho_5.(abridged)

The degeneracy of galaxy formation models

We develop a new formalism for modeling the formation and evolution of galaxies within a hierarchical universe. Similarly to standard semi-analytical models we trace galaxies inside dark-matter merger-trees. The formalism includes treatment of feedback, star-formation, cooling, smooth accretion, gas stripping in satellite galaxies, and merger-induced star bursts. However, unlike in other models, each process is assumed to have an efficiency which depends only on the host halo mass and redshift. This allows us to describe the various components of the model in a simple and transparent way. By allowing the efficiencies to have any value for a given halo mass and redshift, we can easily encompass a large range of scenarios. To demonstrate this point, we examine several different galaxy formation models, which are all consistent with the observational data. Each model is characterized by a different unique feature: cold accretion in low mass haloes, zero feedback, stars formed only in merger-induced bursts, and shutdown of star-formation after mergers. Using these models we are able to examine the degeneracy inherent in galaxy formation models, and look for observational data that will help to break this degeneracy. We show that the full distribution of star-formation rates in a given stellar mass bin is promising in constraining the models. We compare our approach in detail to the semi-analytical model of De Lucia & Blaizot. It is shown that our formalism is able to produce a very similar population of galaxies once the same median efficiencies per halo mass and redshift are being used. We provide a public version of the model galaxies on our web-page, along with a tool for running models with user-defined parameters. Our model is able to provide results for a 62.5 h^{-1} Mpc box within just a few seconds.

The Edge-On Perspective of Bulgeless, Simple Disk Galaxies

ABSTRACTThis review focuses on flat and superthin galaxies. These are edge-on bulgeless galaxies, which are composed of a simple, stellar disk. The properties of these simple disks are at the end of a continuum that extends smoothly from bulge-dominated disk galaxies to the pure disks. On average, simple disks are low-mass galaxies with low surface brightnesses, blue colors, and slow rotational velocities. Widely-accepted cosmological models of galaxy formation and evolution were challenged by a relatively large observed fraction of pure disk galaxies, and only very recent models can explain the existence of simple disk galaxies. This makes simple disks an optimal galaxy type for the study of galaxy formation in a hierarchical universe. They enable us to analyze the environmental and internal influence on galaxy evolution, to study the stability of the disks, and to explain the nature and distribution of dark matter in galaxies. This review summarizes the current status of edge-on simple disk galaxies in the universe.

Massive, red galaxies in a hierarchical universe - I. Counts of extremely red objects and basic properties

We present predictions for the abundance and nature of Extremely Red Objects (EROs) in the Lambda cold dark matter model. EROs are red, massive galaxies observed at z>= 1 and their numbers and properties pose a challenge to hierarchical galaxy formation models. We compare the predictions from two published models, one of which invokes a "superwind" to regulate star formation in massive haloes and the other which suppresses gas cooling in haloes through "radio-mode" AGN feedback. The superwind model underestimates the number counts of EROs by an order of magnitude, whereas the radio-mode AGN feedback model gives excellent agreement with the number counts and redshift distribution of EROs. In the AGN feedback model the ERO population is dominated by old, passively evolving galaxies, whereas observations favour an equal split between old galaxies and dusty starbursts. Also, the model predicts a more extended redshift distribution of passive galaxies than is observed. These comparisons suggest that star formation may be quenched too efficiently in this model.

The Effects of Galactic Winds on the Chemical Evolution of Baryons

AbstractDuring the last decade, the development of more sophisticated surveys allows the exploration of the chemical enrichment of galaxies and their environment at different cosmic times. In this context, it has been suggested that galactic winds play a fundamental role in the regulation of the star formation and the transportation of metals outside the galaxies. In this work, we study the influence of Supernovae winds in the chemical evolution of galaxies and the intergalactic medium by employing cosmological numerical simulations within a hierarchical Universe. We focus on the origin and evolution of the mass-metallicity relation (MZR).

Generalizing the Random Walk and the Eddington–Weinberg laws for a hierarchical Universe

In this paper, we propose generalizations of the Random Walk and Eddington–Weinberg laws on the basis of a hierarchical, rather than fractal, geometry of the Universe. Evidence of the hierarchical evolution of the expanding Universe clearly emerges by a comparison with highly different-sized astrophysical, solar, biological and atomistic objects.

Formation ofz∼6 Quasars from Hierarchical Galaxy Mergers

The discovery of luminous quasars at redshift z ~ 6 indicates the presence of supermassive black holes (SMBHs) of mass ~109 M? when the universe was less than 1 billion years old. This finding presents several challenges for theoretical models because whether such massive objects can form so early in the ?CDM cosmology, the leading theory for cosmic structure formation, is an open question. Furthermore, whether the formation process requires exotic physics such as super-Eddington accretion remains undecided. Here we present the first multiscale simulations that, together with a self-regulated model for the SMBH growth, produce a luminous quasar at z ~ 6.5 in the ?CDM paradigm. We follow the hierarchical assembly history of the most massive halo in a ~3 Gpc3 volume and find that this halo of ~8 ? 1012 M? forming at z ~ 6.5 after several major mergers is able to reproduce a number of observed properties of SDSS J1148+5251, the most distant quasar detected at z = 6.42 (Fan et al. 2003). Moreover, the SMBHs grow through gas accretion below the Eddington limit in a self-regulated manner owing to feedback. We find that the progenitors experience vigorous star formation (up to 104 M? yr-1) preceding the major quasar phase such that the stellar mass of the quasar host reaches 1012 M? at z ~ 6.5, consistent with observations of significant metal enrichment in SDSS J1148+5251. The merger remnant thus obeys a similar MBH-Mbulge scaling relation observed locally as a consequence of coeval growth and evolution of the SMBH and its host galaxy. Our results provide a viable formation mechanism for z ~ 6 quasars in the standard ?CDM cosmology and demonstrate a common, merger-driven origin for the rarest quasars and the fundamental MBH-Mbulge correlation in a hierarchical universe.

The effect of gravitational recoil on black holes forming in a hierarchical universe

Galactic bulges are known to harbour central black holes whose mass is tightly correlated with the stellar mass and velocity dispersion of the bulge. In a hierarchical universe, galaxies are built up through successive mergers of subgalactic units, a process that is accompanied by the amalgamation of bulges and the likely coalescence of galactocentric black holes. In these mergers, the beaming of gravitational radiation during the plunge phase of the black hole collision can impart a linear momentum kick or ‘gravitational recoil’ to the remnant. If large enough, this kick will eject the remnant from the galaxy entirely, and populate intergalactic space with wandering black holes. Using a semi-analytic model of galaxy formation, we investigate the effect of black hole ejections on the scatter of the relation between black hole and bulge mass. We find that while not being the dominant source of the measured scatter, they do provide a significant contribution and may be used to set a constraint, vkick≲ 500 km s−1, on the typical kick velocity, in agreement with values found from general relativistic calculations. Even for the more modest kick velocities implied by these calculations, we find that a substantial number of central black holes are ejected from the progenitors of present-day galaxies, giving rise to a population of wandering intrahalo and intergalactic black holes whose distribution we investigate in high-resolution N-body simulations of the Milk Way mass haloes. We find that intergalactic black holes make up only ∼2–3 per cent of the total galactic black hole mass but, within a halo, wandering black holes can contribute up to about half of the total black hole mass orbiting the central galaxy. Intrahalo black holes offer a natural explanation for the compact X-ray sources often seen near the centres of galaxies and for the hyperluminous non-central X-ray source in M82.

The Origin of Polar Ring Galaxies: Evidence for Galaxy Formation by Cold Accretion

Polar ring galaxies are flattened stellar systems with an extended ring of gas and stars rotating in a plane almost perpendicular to the central galaxy. We show that their formation can occur naturally in a hierarchical universe where most low-mass galaxies are assembled through the accretion of cold gas infalling along megaparsec-scale filamentary structures. Within a large cosmological hydrodynamical simulation, we find a system that closely resembles the classic polar ring galaxy NGC 4650A. How galaxies acquire their gas is a major uncertainty in models of galaxy formation, and recent theoretical work has argued that cold accretion plays a major role. This idea is supported by our numerical simulations and the fact that polar ring galaxies are typically low-mass systems.

The Formation of Fossil Galaxy Groups in the Hierarchical Universe

We use a set of twelve high-resolution N-body/hydrodynamical simulations in the $\Lambda$CDM cosmology to investigate the origin and formation rate of fossil groups (FGs), which are X-ray bright galaxy groups dominated by a large elliptical galaxy, with the second brightest galaxy being at least two magnitudes fainter. The simulations invoke star formation, chemical evolution with non-instantaneous recycling, metal dependent radiative cooling, strong star burst driven galactic super winds, effects of a meta-galactic UV field and full stellar population synthesis. We find an interesting correlation between the magnitude gap between the first and second brightest galaxy and the formation time of the group. It is found that FGs have assembled half of their final dark matter mass already at $z\ga1$, and subsequently typically grow by minor merging only, wheras non-FGs on average form later. The early assembly of FGs leaves sufficient time for galaxies of $L \sim L_*$ to merge into the central one by dynamical friction, resulting in the large magnitude gap at $z=0$. A fraction of 33$\pm$16% of the groups simulated are found to be fossil, whereas the observational estimate is $\sim$10-20%. The FGs are found to be X-ray over-luminous relative to non-FGs of the same optical luminosity, in qualitative agreement with observations. Finally, from a dynamical friction analysis is found that only because infall of $L \sim L_*$ galaxies happens along filaments with small impact parameters do FGs exist at all.

Testing the Universality of the (U−V) Color‐Magnitude Relations for Nearby Clusters of Galaxies

We present a detailed (U - V) color-magnitude relation (CMR) analysis for three local (z < 0.06) clusters of galaxies. From square-degree imaging of the Abell clusters A85, A496, and A754, we select 637 galaxies down to L ~ 0.1L with spectroscopic membership, which minimizes uncertain field contamination corrections. To characterize the degree of CMR uniformity among nearby clusters, we use a maximum likelihood technique to quantify the CMR properties of the red galaxies in each cluster. We find that these clusters have similar CMRs with a mean color of (U - V) = 1.40 at MV = -20 + 5 h and narrow limits of intrinsic color scatter [0.047, 0.079] and slope [-0.094, -0.075]. If we restrict our analysis to the core cluster population of red galaxies, the resulting CMRs are in close agreement with that of the Coma Cluster, the only local cluster with a rest-frame (U - V) CMR determination of comparable precision. Therefore, the CMR uniformity of present-day clusters spans a fairly wide range of cluster masses. We test how sensitive the CMR uniformity is to variations in color aperture size and sample selection, and we find at most slightly wider limits of scatter [0.047, 0.112] and slope [-0.104, -0.054]. This upper limit for (U - V) scatter is consistent with the bulk of the stellar populations of red cluster galaxies forming before z = 1.2, with a maximum age spread of 5.2 Gyr. In addition, we note that using colors from apertures containing equal fractions of galactic light does not remove the CMR slope and that none of the slopes exhibit a break as claimed by Metcalf and coworkers. Our findings expand the single Coma data point and provide a much needed z = 0 baseline for comparisons to high-redshift cluster CMRs at the same rest-frame wavelengths. The range in CMR scatter that we find among nearby clusters is consistent with the values reported for clusters at higher redshifts, further suggesting that there has been little evolution in the stellar populations of red-sequence cluster galaxies out to at least z ~ 1. To identify the most recently accreted cluster galaxies, we divide each cluster's membership into three galaxy populations based on (U - V) color relative to the well-defined CMR. Blue and moderately blue galaxies make up 18%-23% by number of each cluster population more luminous than 0.1L*. Our color-magnitude division should represent a rough time since cluster accretion. In testing this hypothesis, we find that blue galaxies are spatially, kinematically, and morphologically distinct from red cluster galaxies. Even in projection, the blue galaxies reside toward the outskirts of the cluster and appear to avoid the inner half-megaparsec, in contrast with the increasing density of red-sequence galaxies toward the cluster center. In addition, the blue galaxies have velocity distributions relative to the cluster rest frame that are flatter, and some have different means, compared to the roughly Gaussian distribution of red member velocities. Members with the bluest colors tend to be disklike or irregular in appearance compared to the red galaxies, which have mostly early-type (E/S0) morphologies. Moderately blue cluster galaxies may be an intermediate mix with a fraction of small bulge-to-disk ratio S0s, yet these require closer scrutiny. The spatial, kinematic, and morphological distinctions between blue and red cluster galaxies provide further evidence that CMR-relative color is related to time since cluster infall and that bluer members are indeed the most recently accreted field spirals as expected in a hierarchical universe.

On the formation of globular cluster systems in a hierarchical Universe

ABSTRA C T We have investigated the formation of globular cluster (GC) systems in the fiducial semianalytic model of galaxy formation of Cole et al., by assuming that GCs are formed at high redshifts ﷿z . 5fi in protogalactic fragments, and during the subsequent gas-rich merging of these fragments. Under these assumptions we have simulated the GC systems of 450 elliptical galaxies, and find that the majority (93 per cent) are intrinsically bimodal in metallicity. We find that, in the mean, the metal-rich GC subpopulations are younger than the metal-poor GC subpopulations, with ages of 9 and 12 Gyr respectively, and that the mean ages of the metalrich GCs are dependent upon host galaxy luminosity and environment (halo circular velocity), whereas the metal-poor GCs are not. We find that the continued gaseous merging of the protogalactic fragments leads to significant age-structure amongst the metal-rich GCs. These GCs exhibit a large age-range (5 to 12 Gyr), which increases for low-luminosity galaxies, and for galaxies in low circular velocity haloes. Moreover, the metal-rich GCs associated with low-luminosity field and/or group ellipticals are , 2 Gyr younger than the metal-rich GCs in luminous cluster ellipticals. We find that the total GC populations scale with host galaxy luminosity as NGC / L 1:25 V;gal , a result in agreement with observations of luminous elliptical galaxies. This scaling is due to a systematic increase in the M/L ratios of the galaxy haloes with luminosity for LV;gal . L * galaxies in the model. A comparison between the luminosity growth of the model ellipticals and their GC formation indicates that mergers do not significantly affect SN at z , 2. We find the mean colours of the both the metal-rich and metal-poor GCs exhibit only a weak dependence upon host galaxy luminosity, a result consistent with contemporary observations. We conclude that gaseous merging, the bulk of which occurs at 1 # z # 4i n ourLCDM model, leads to the formation of the metalrich peak of the GC systems of elliptical galaxies. We suggest that the formation and subsequent truncation of the metal-poor GCs in the protogalactic fragments is closely related to the star formation rate in these fragments, which may have been significantly higher at very early times.

The pinocchio algorithm: pinpointing orbit-crossing collapsed hierarchical objects in a linear density field

ABSTRA C T PINOCCHIO (PINpointing Orbit-Crossing Collapsed HIerarchical Objects) is a new algorithm proposed recently by Monaco et al. (Paper I) for identifying dark matter haloes in a given numerical realization of the linear density field in a hierarchical universe. Mass elements are assumed to have collapsed after undergoing orbit crossing, as computed using perturbation theory. It is shown that Lagrangian perturbation theory, and in particular its ellipsoidal truncation, is able to predict accurately the collapse, in the orbit-crossing sense, of generic mass elements. Collapsed points are grouped into haloes using an algorithm that mimics the hierarchical growth of structure through accretion and mergers. Some points that have undergone orbit crossing are assigned to the network of filaments and sheets that connects the haloes; it is demonstrated that this network resembles closely that found in N-body simulations. The code generates a catalogue of dark matter haloes with known mass, position, velocity, merging history and angular momentum. It is shown that the predictions of the code are very accurate when compared with the results of large N-body simulations that cover a range of cosmological models, box sizes and numerical resolutions. The mass function is recovered with an accuracy of better than 10 per cent in number density for haloes with at least 30 ‐ 50 particles. A similar accuracy is reached in the estimate of the correlation length r0. The good agreement is still valid on the object-by-object level, with 70 ‐ 100 per cent of the objects with more than 50 particles in the simulations also identified by our algorithm. For these objects the masses are recovered with an error of 20 ‐ 40 per cent, and positions and velocities with a root mean square error of ,1 ‐2 MpcO0:5 ‐ 2 grid lengths) and ,100 km s 21 , respectively. The recovery of the angular momentum of haloes is considerably noisier, and accuracy at the statistical level is achieved only by introducing free parameters. The algorithm requires negligible computer time as compared with performing a numerical N-body simulation.

Do Clusters Contain a Large Population of Dwarf Galaxies?

We analyze systematic effects in the determination of the galaxy luminosity function in clusters using a deep mock catalog constructed from a numerical simulation of a hierarchical universe. The results indicate a strong tendency to derive a rising faint end (α -1.5) in clusters selected in two dimensions, using a galaxy catalog constructed with a universal flat luminosity function with α -1.0. This is a result of the projection effects inherent in catalogs of clusters constructed using two-dimensional data. Many of the clusters found in two dimensions have no significant three-dimensional counterparts, and most suffer from massive background contamination that cannot be corrected for by subtracting random offset fields. The luminosity function of high surface brightness galaxies in the field and within small groups follows a Schechter function with a fairly flat faint-end slope, n(L) Lα, with α = -0.9 to -1.2. On the contrary, observational studies of clusters constructed using Abell, EDCC, and APM catalogs are systematically found to have steeper luminosity functions with α = -1.4 to -2.0. This may be attributed to projection effects rather than a dominant population of high surface brightness dwarf galaxies (M M* + 2) in clusters. It should be straightforward to confirm our results by measuring redshifts of these faint cluster galaxies.

Cold collapse and the core catastrophe

We show that a universe dominated by cold dark matter fails to reproduce the rotation curves of dark matter dominated galaxies, one of the key problems that it was designed to resolve. We perform numerical simulations of the formation of dark matter haloes, each containing ≳106 particles and resolved to 0.003 times the virial radius, allowing an accurate comparison with rotation curve data. A good fit to both Galactic and cluster-sized haloes can be achieved using the density profile ρ(r)∝[(rrs)1.5(1+(rrs)1.5)]−1, where rs is a scale radius. This profile has a steeper asymptotic slope, ρ(r)∝r−1.5, and a sharper turn-over than found by lower resolution studies. The central structure of relaxed haloes that form within a hierarchical universe has a remarkably small scatter. We compare the results with a sample of dark matter dominated, low surface brightness (LSB) galaxies with circular velocities in the range 100–300 km s−1. The rotation curves of discs within cold dark matter haloes rise too steeply to match these data, which require a constant mass density in the central regions. The effects of Ωmass and Λ cannot reconcile the cold dark matter (CDM) model with data - even if we leave the concentration as a free parameter, we are unable to reproduce the observations with such a steep central density profile. It is important to confirm these results using stellar rather than H i rotation curves for LSB galaxies. We test the effects of introducing a cut-off in the power spectrum that may occur in a universe dominated by warm dark matter. In this case, haloes form by a monolithic collapse but the final density profile barely changes, demonstrating that the merger history does not play a role in determining the halo structure.

Dark Matter Substructure within Galactic Halos

We use numerical simulations to examine the substructure within galactic and cluster mass halos that form within a hierarchical universe. Clusters are easily reproduced with a steep mass spectrum of thousands of substructure clumps that closely matches observations. However, the survival of dark matter substructure also occurs on galactic scales, leading to the remarkable result that galaxy halos appear as scaled versions of galaxy clusters. The model predicts that the virialised extent of the Milky Way's halo should contain about 500 satellites with circular velocities larger than Draco and Ursa-Minor i.e. bound masses > 10^8Mo and tidally limited sizes > kpc. The substructure clumps are on orbits that take a large fraction of them through the stellar disk leading to significant resonant and impulsive heating. Their abundance and singular density profiles has important implications for the existence of old thin disks, cold stellar streams, gravitational lensing and indirect/direct detection experiments.

Clustering of galaxies in a hierarchical universe -- I. Methods and results at z = 0

We introduce a new technique for following the formation and evolution of galaxies in cosmological N-body simulations. Dissipationless simulations are used to track the formation and merging of dark matter haloes as a function of redshift. Simple prescriptions, taken directly from semi-analytic models of galaxy formation, are adopted for gas cooling, star formation, supernova feedback and the merging of galaxies within the haloes. This scheme enables us to explore the clustering properties of galaxies, and to investigate how selection by luminosity, colour or type influences the results. In this paper we study the properties of the galaxy distribution at z=0. These include B- and K-band luminosity functions, two-point correlation functions, pairwise peculiar velocities, cluster mass-to-light ratios, B-V colours, and star formation rates. We focus on two variants of a cold dark matter (CDM) cosmology: a high-density (Ω =1) model with shape-parameter Γ =0.21 (τ CDM), and a low-density model with Ω =0.3 and λ =0.7 (λ CDM). Both models are normalized to reproduce the I-band Tully--Fisher relation of Giovanelli et al. near a circular velocity of 220 km s−1. Our results depend strongly both on this normalization and on the adopted prescriptions for star formation and feedback. Very different assumptions are required to obtain an acceptable model in the two cases. For τ CDM, efficient feedback is required to suppress the growth of galaxies, particularly in low-mass field haloes. Without it, there are too many galaxies and the correlation function exhibits a strong turnover on scales below 1 Mpc. For λ CDM, feedback must be weaker, otherwise too few L* galaxies are produced and the correlation function is too steep. Although neither model is perfect, both come close to reproducing most of the data. Given the uncertainties in modelling some of the critical physical processes, we conclude that it is not yet possible to draw firm conclusions about the values of cosmological parameters from studies of this kind. Further observational work on global star formation and feedback effects is required to narrow the range of possibilities.

The Galaxy Cluster Luminosity-Temperature Relationship and Iron Abundances: A Measure of Formation History?

Both the X-ray luminosity-temperature (L-T) relationship and the iron abundance distribution of galaxy clusters show intrinsic dispersion. Using a large set of galaxy clusters with measured iron abundances, we find a correlation between abundance and the relative deviation of a cluster from the mean L-T relationship. We argue that these observations can be explained by taking into account the range of cluster formation epochs expected in a hierarchical universe. The known relationship of cooling flow mass deposition rate to luminosity and temperature is also consistent with this explanation. From the observed cluster population, we estimate that the oldest clusters formed at z 2. We propose that the iron abundance of a galaxy cluster can provide a parameterization of its age and dynamical history.

A. R. Ammons's Stevensian Search for a Supreme Fiction in Sphere

Our own time, and by this mean the last two or three generations, including our own, can be summed up in a way that brings into unity an immense number of details by saying of it that it is a time in which the search for the truth has been a search in reality or reality or even a search for supremely acceptable fiction. - Wallace Stevens, Necessary Angel (NA) 173 Ammons claims that Emerson and Whitman are his most immediate forebears (Grossvogel 51). Evidence for the validity of this claim is his long-standing search for a poetics capable of accommodating the most inclusive vision of reality. Always striving assimilate the unassimilated, keep the and the many in a balanced perspective, he attempts rediscover how he himself is part of a completely interconnected universe. Yet this search for an inclusive poetics, which culminates in his long poem Sphere, reveals the influence of another major poet. When Ammons in Sphere alludes Wallace Stevens and suggests that if truth is colorless fictions / need be supreme (S 57),(1) he further defines his preoccupation with inclusiveness as a search for some supremely acceptable that will serve as a unifying mythos. This allusion prompts a reading of Sphere as Ammons's own notes toward a fiction - a reading that shows that his major preoccupations in this poem have virtually identical counterparts in the poetry of Stevens. Both poets are preoccupied with accommodating the unlimited possibilities of reality, the relationship between the earthly and the celestial, and the idea that the ultimate poetry must be abstract. Such preoccupations pervade Ammons's canon - from his earliest volume, Ommateum, his latest, Garbage - but register their strongest signal in Sphere. In this volume, they are repeated and modulated in a number of different contexts and combine create an unmistakably Stevensian poetics, which Ammons assimilates his own vision. My discussion will focus how Ammons's treatment of these preoccupations acknowledges the legacy of Stevens and the same time points toward a new vision of a fiction. By appropriating the poetry of Stevens his own poetics, Ammons sees the fiction as revealing our sense of place in a hierarchical universe where the divinely ordering forces of what he calls the Most High (S 69) are extensions of ourselves. Sphere, then, somewhat mitigates Stevens's liminal war between the mind / And sky (Collected Poems [CP] 407). As we find ourselves immersed in Ammons's verbal concatenations stretching from the atom the highest levels of pure energy, we feel the possibility of a more sustained union between self and world. This is a unifying mythos, which, as will argue, owes a great debt Stevens's insistence writing a poetry of earth. Ammons makes it quite clear that intuitions of the Most High begin with a desire to appreciate the lesser celandine (S 82); and surely Stevens is somewhere behind his suggestion that wherever the imagined lands it's / likely brush up against a thorn (S 59). In the heterocosmic world of Sphere, Ammons's continual preoccupation with what he calls his one many problem (S 4) - the need assimilate particulars within patterns - is still his primary motivation for achieving a poetics of accommodation. Ammons avoids imposing any artificial unity a transformative world by focusing process rather than taxonomy (Clark 1). Recalling his own Essay Poetics, he describes the progression from cell water energy spirit as a movement through the discrete the general (S 9), and suggests further that he himself is a part of this progression that inevitably connects him all other forms of life: I could not say, then, that the earthworm is not / my radical cousin (S 10). Given this sense of the interconnectedness of all things - how The unassimilable fact leads us on (Selected Poems [SP] 32) - Ammons is wary of the idea of fixed boundaries, for he asks: at what aural / remove from the actual leaf does light cease be tree (S 25). …