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Understanding the Generalized Fefferman-Graham Gauge in Gravity

A look into the gFG gauge and its significance in theoretical physics.

Gabriel Arenas-Henriquez, Felipe Diaz, David Rivera-Betancour

― 5 min read


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In the world of theoretical physics, understanding how different spaces work, especially in relation to gravity, is a complex puzzle. One method that physicists use is the AdS/CFT correspondence, which helps relate theories of gravity to those in quantum field theory. This is like connecting a heavy book to a light feather-both can tell us something about the universe, just in very different ways.

One of the tools in this toolbox is the Fefferman-Graham (FG) gauge. This gauge helps express certain spaces known as asymptotically anti-de Sitter spaces. Imagine walking up a hill where the view changes as you go higher-this gauge gives clarity to the boundary structure of these spaces. However, choosing a specific boundary condition in this method can sometimes mess up some symmetries, like stepping on a leaf and suddenly losing balance.

Recently, scientists have made progress by introducing a new way to think about these boundary conditions, called the Weyl-Fefferman-Graham (WFG) gauge. This new approach is like discovering a new path up that same hill-one that maintains balance and keeps the view intact. The focus here is on three-dimensional gravity, which, at first glance, looks pretty simple, but this simplicity can be deceiving.

The Magic of Boundary Weyl Structures

So what's all this fuss about boundary Weyl structures? Imagine they are the invisible threads that hold together the tapestry of spacetime. When we talk about boundaries in gravity, we're often looking at how things behave at the edges of these spaces. By using the WFG gauge, we can preserve these important structures, which in turn helps us study more complex systems, like accelerating black holes.

You might think black holes are just big cosmic vacuums, but they have their own stories to tell. Understanding how gravity plays with these black holes gives us insights into much more complicated ideas, like what's happening deep down in the quantum world.

The Holographic Renormalization Scheme

The holographic renormalization scheme sounds fancy, but at its core, it’s about removing the messiness that comes with calculating the properties of physical systems. Like cleaning your room before friends come over, this method helps us extract meaningful information from what could otherwise be a chaotic space.

When looking at gravitational actions within this framework, new surprising divergences pop up-think of them as unexpected guests at a party. To manage these, scientists introduce counterterms, which serve as party favors that keep everything under control.

Diving into the Boundary Theory

Now, let’s talk about the boundary theory, or the stuff happening at the edge of these cosmic lands. In the standard setup, the boundary theory gets a little complicated because we need to pick a specific representative of the boundary metric, which can skew our results. It’s like trying to take a group photo but everyone is standing at different angles.

The WFG gauge clears this up by allowing us to introduce Weyl connections. Imagine these as the group photo editor that helps everyone line up nicely. This way, the theory is no longer just a mess of angles, but a coherent picture of what's going on.

Gravity and Its Twists

Three-dimensional gravity is a unique case. While in higher dimensions gravity can be quite dynamic, in three dimensions it’s more like a sculpture-beautiful but lacking in movement. Still, it has its uses as a model to explore deeper questions about quantum gravity.

One way to see this is through something called the Partition Function. This function encodes information about how the system behaves. However, scientists have discovered that when we work with three-dimensional gravity, the partition function can lead to strange, non-physical results, like a balloon that won’t pop no matter how much air you put in.

To get around this, scientists delve into new contributions from topological defects-those sneaky little glitches that can change everything about the way gravity behaves.

Uncovering the gFG Gauge

Here comes the generalized Fefferman-Graham (gFG) gauge! This gauge takes the WFG gauge and pushes it a little further, allowing for even more flexibility. It’s like getting an upgrade from a bike to a motorcycle-now we can zoom around and explore new terrains.

The gFG gauge sets us up to analyze boundary Weyl structures properly. For many, this might seem like a wild chase into the unknown, but the payoff could be worth it. With this in hand, scientists can study even wilder phenomena, such as accelerating black holes. But do not worry; we won’t leave you hanging as we dive into the details.

The Road Ahead: Applications Galore

Having established the gFG gauge is a great start, but what does this mean for the universe of physics? Here, examples of topologically interesting spaces come into play, which is basically a way of saying, "Hey, let’s look at the weird shapes and sizes of things!"

One of the shining stars in this exploration is the accelerating black hole. These are more than just cosmic whirlpools; they are like the cool kids at the party who have stories of their own. The gFG gauge helps make sense of the bizarre nature of these black holes, revealing new twists and turns along the way.

Wrapping Up

In summary, we’ve journeyed through the complex world of the gFG gauge and its relationship with boundary Weyl structures. Along the way, we’ve tidied up our understanding and found ways to navigate the sometimes-chaotic seas of theoretical physics. We’ve even managed to snag a glimpse at strange and wonderful phenomena like accelerating black holes, all while keeping our balance on the cosmic tightrope.

So, as we look ahead, remember that the universe is like a grand party-with infinite mysteries waiting to be unraveled. And just like at any gathering, the more you explore, the more fascinating stories you will uncover. Happy exploring!

Original Source

Title: Generalized Fefferman-Graham gauge and boundary Weyl structures

Abstract: In the framework of AdS/CFT correspondence, the Fefferman--Graham (FG) gauge offers a useful way to express asymptotically anti-de Sitter spaces, allowing a clear identification of their boundary structure. A known feature of this approach is that choosing a particular conformal representative for the boundary metric breaks explicitly the boundary scaling symmetry. Recent developments have shown that it is possible to generalize the FG gauge to restore boundary Weyl invariance by adopting the Weyl--Fefferman--Graham gauge. In this paper, we focus on three-dimensional gravity and study the emergence of a boundary Weyl structure when considering the most general AdS boundary conditions introduced by Grumiller and Riegler. We extend the holographic renormalization scheme to incorporate Weyl covariant quantities, identifying new subleading divergences appearing at the boundary. To address these, we introduce a new codimension-two counterterm, or corner term, that ensures the finiteness of the gravitational action. From here, we construct the quantum-generating functional, the holographic stress tensor, and compute the corresponding Weyl anomaly, showing that the latter is now expressed in a full Weyl covariant way. Finally, we discuss explicit applications to holographic integrable models and accelerating black holes. For the latter, we show that the new corner term plays a crucial role in the computation of the Euclidean on-shell action.

Authors: Gabriel Arenas-Henriquez, Felipe Diaz, David Rivera-Betancour

Last Update: 2024-11-22 00:00:00

Language: English

Source URL: https://arxiv.org/abs/2411.12513

Source PDF: https://arxiv.org/pdf/2411.12513

Licence: https://creativecommons.org/licenses/by/4.0/

Changes: This summary was created with assistance from AI and may have inaccuracies. For accurate information, please refer to the original source documents linked here.

Thank you to arxiv for use of its open access interoperability.

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